Abstract:
An application control system for use in a vehicle includes a current region detector for detecting a current region where the vehicle is operating, an application storage for storing a regional application software in association with a preset region and a control unit for retrieving and executing the regional application software stored in the application storage based on the current region detected by the current region detector. The control unit retrieves and executes the regional application software when the current region is identified as the preset region.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based on and claims the benefit of priority of Japanese Patent Application No. 2005-309906 filed on Oct. 25, 2005, the disclosure of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention generally relates to a vehicular navigation system. 
     BACKGROUND OF THE INVENTION 
     In recent years, a navigation system uses an application software for retrieving map data from information medium such as DVD-ROM or the like and displaying it on a display unit. In this case, the application software has to be switched depending on a format of the map data provided by the DVD-ROM. For example, when the map data is prepared by using a format 1.0 in a region A and by using a format 2.0 in a region B, different types of application software have to be used respectively in each of the region A and region. B to accommodate the difference of data format. The map data in each of the format 1.0 and format 2.0 is retrieved from the medium such as the DVD-ROM, a HDD or the like and is loaded in a memory under a control of a CPU when a user, or a driver of a vehicle, uses the navigation system. The application software used in the navigation system is also retrieved from the medium to the memory of the navigation system. 
     The application software executed in, for example, a substrate  1  of the navigation system in  FIG. 7A  is conventionally determined based on an input of a divided voltage Vd that is applied to a reference input terminal of a CPU  2  after dividing a source voltage Vc by using a series circuit of resistors  3 ,  4 . That is, the CPU  2  determines the application software to be used in the navigation system based on the input of a signal that is derived from A/D conversion of the divided voltage Vd. The input to the CPU  2  may be provided as an ID code from a ROM  5  coupled with the CPU  2  when the navigation system is initialized. 
     Thus, the conventional navigation system has to have a different product series for respective regions (i.e., for respective data formats) due to above-described operation scheme. That is, the navigation system having the application software designated for each region has to be produced as a different series of products because the application software for a specific region (i.e., for a specific data format) is selected and determined based on a product code of the navigation system. As a result, an increased number of versions of the navigation system leads to a complicated situation such as a version control in a production operation, an inventory operation or the like. 
     The navigation system disclosed in Japanese patent document JP-A-H10-208194 has an operation scheme that the navigation system in operation determines and switches product specifications based on a current position of the navigation system detected by using map data. 
     However, the navigation system in the above disclosure suffers from difference of map data format. That is, the navigation system does not work properly when the map data for the current position is provided in a format that is not compatible with the application software used in the navigation system. 
     SUMMARY OF THE INVENTION 
     In view of the above-described and other problems, the present disclosure provides an application control system that uses different types of application software for different regions without compromising usability in trans-regional use and simplicity in product version control. 
     In one aspect of the present disclosure, the application control system for use in a vehicle includes a current region detector for detecting a current region where the vehicle is operating, an application storage for storing a regional application software in association with a preset region and a control unit for retrieving and executing the regional application software stored in the application storage based on the current region detected by the current region detector. The control unit retrieves and executes the regional application software when the current region is identified as the preset region. 
     The application control system having the operation scheme described above can retrieve a different type of the application software for different region, thereby enabling a single model of a specific product (e.g., a navigation system) to cover multiple regions that requires respectively different types of application software. Therefore, production cost of the product is reduced. 
     Further, the control unit controls the retrieval of the application software that is suitable to the region where the specific product is operated for the first time. In this manner, the suitability of the application software to the region of the operation is securely guaranteed. 
     In another aspect of the present disclosure, the application software is adaptively switched by the application control system according to the region where the application software is operated. In this manner, execution of the application software is always suitably maintained to the region of the operation even when a parent system of the application software travels from region to region. 
     In yet another aspect of the present disclosure, the switching timing of the application software is adaptively controlled based on a predetermined condition such as a travel distance, a travel time of the parent system. In this manner, stable execution of the application software and the parent system is guaranteed even when the parent system of the application software frequently crosses a border of the different regions. In addition, the predetermined condition can be controlled to achieved an improved operation condition of the application software and/or the parent system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which: 
         FIG. 1  shows a block diagram of an application control system in a first embodiment of the present disclosure; 
         FIG. 2  shows a flowchart of a control process of the application control system; 
         FIG. 3  shows a table of relationship between regions and application types; 
         FIG. 4  shows a flowchart of the control process of the application control system in a traveling condition; 
         FIG. 5  shows a flowchart of the control process of the application control system in a traveling condition in a second embodiment; 
         FIG. 6  shows a flowchart of the control process of the application control system in a traveling condition in a third embodiment; and 
         FIGS. 7A and 7B  shows illustrations of a substrate in a conventional system. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present disclosure are described with reference to the drawings. The embodiments of the present disclosure are not necessarily limited to the types/forms in the present embodiment, but may take any form of the art or technique that is regarded within the scope of the present disclosure by artisans who have ordinary skill in the art. 
     (First Embodiment) 
     A first embodiment of an application control system in the present disclosure is described as a vehicle navigation system with reference to  FIGS. 1 to 4 . 
       FIG. 1  shows a block diagram of the navigation system  11  in a first embodiment of the present disclosure. The block diagram shows an electrical connection between components in the navigation system  11 . The navigation system  11  has a control unit  12  including a CPU, a ROM, a RAM, an interface circuit and programs for navigation functions stored therein for providing route navigation for a user based on a user input. 
     The control unit  12  has a connection to a GPS receiver  13  and various sensors such as a speed sensor  14 , an angular speed sensor  15 , a G sensor (an acceleration sensor)  16  and the like. The control unit  12  detects and calculates a current region (a current position) of the vehicle based on a GPS signal from a satellite received by the GPS receiver  13 . The current position of the vehicle is accurately determined by employing signals from the speed sensor  14 , the angular velocity sensor  15 , the G sensor  16 . 
     The control unit  12  also has a connection to a communication unit  17 , a display unit  18 , an operation switch  19 , a speaker  20 , a memory  21 , and a storage medium  22 . The storage medium  22  is used as a medium for provision of application software. The communication unit  17  has a function of a cellular phone for providing communication with an external network and the like. The display unit  18  has a liquid crystal display panel and the like for displaying a signal from the control unit  12 . The display unit  18  also has a touch panel disposed thereon for implementing the operation switch  19 . The operation switches  19  are also implemented as a mechanical switches arranged around the display unit  18 . 
     The speaker  20  is used to output navigation guidance voice synthesized by the navigation system, and other guidance voices for notification or the like. The memory  21  is used to store setting information and other information. The memory  21  is also used to as a database for storing travel condition information. The memory  21  uses non-volatile memory device such as an EEPROM or the like for storing information. The storage medium  22  is, for example, information medium such as a CD-ROM, a DVD-ROM or the like for storing map data and-application software for displaying the map data. The information in the storage medium  22  is retrieved by using a data reader (not shown in the figure). 
     The operation of the navigation system  11  is described with reference to  FIGS. 2 to 4 . Functions of the navigation system beside route navigation function accompanied by map display based on an inputted destination and a current position of the vehicle are omitted from the description for brevity, while characteristics of the present disclosure are described in detail in the following. 
     The navigation system  11  starts its operation in the following manner. That is, when a power of the navigation system  11  is turned on, the control unit  12  starts its operation and executes an operation instruction stored in a loader in the ROM of the memory  21 . The execution process of the operation instruction is described as a flowchart in  FIG. 2 . 
     In step S 1 , the process in the control unit  12  detects a current position of the vehicle based on the GPS signal received by the GPS receiver  13 . The current position is used to determine a current region where the vehicle is traveling. In steps S 2  and S 3 , the process determines whether the current position is detected and displays a progress message on the display unit  18  during detection of the current position (step S 2 :NO). The process returns to step S 1  after step S 3 . The process proceeds to step S 4  when the current position is detected (step S 2 :YES). 
     In step S 4 , the process determines application software to be retrieved according to the current position detected in step S 1 . In this case, relationship between the current region and the application software are defined by, for example, a table shown in  FIG. 3 . That is, the region A is associated with the application software V1.5, the region B is associated with the application software V2.5, and the region C is associated with the application software V3.5. Each of the application software having various versions is stored in the storage medium  22 . 
     In step S 5 , the process in the control unit  12  determines whether the application software already used in the navigation system  11  is in concord with the definition in the table in  FIG. 3 . The process proceeds to step S 6  when the application software is already used in the navigation system  11  (step S 5 :YES). The process proceeds to step S 7  when the application software in use is different from the definition (step S 5 :NO). 
     In step S 6 , the process executes the application software already in use. 
     In step S 7 , the process determines whether a suitable version of the application software is found in the storage medium  22 . The process proceeds to step S 8  when the suitable version in found in the storage medium  22 . The process proceeds to step S 9  when the suitable version is not found in the storage medium  22 . 
     In step S 8 , the process retrieves the suitable application software and returns to step S 5 . After passing step S 8 , the determination in step S 5  always becomes affirmative (YES), and the process proceeds to step S 6 . 
     In step S 9 , the process displays an error message for notifying a condition that the suitable software is not found in the storage medium  22  due to, for example, a mismatch, an absence of the medium  22  or the software on the medium  22 . The process returns to step S 1  after displaying the error message. 
     The operation of the navigation system  11  in a traveling condition is described with reference to a flowchart in  FIG. 4 . In this flowchart, the control process executed in parallel with a navigation function switches the application software that suitably handles the map data of a region where the vehicle is currently traveling so as to accommodate different map data format in each of the plural regions, that is, in each of the plural countries or the like when the vehicle is traveling across country borders. 
     In steps P 1  to P 3 , the process detects and determines the current position of the vehicle as in steps S 1  to S 3  described before. 
     In step P 4 , the process determines whether the application software in use is suitable for the current region. The process proceeds to step P 5  when the software is suitable (step P 4 :YES), and the process proceeds to step P 7  when the software is not suitable (step P 4 :NO). 
     In steps P 5  and P 6 , the process executes the application software and determines whether navigation process ends. The process proceeds to step P 10  when the navigation process ends (step P 6 :YES), or the process returns to step P 1  when the navigation process is not ending (step P 6 :NO). 
     In step P 7 , the process determines whether the suitable version of the application software is found in the storage medium  22 . The process proceeds to step P 8  when the suitable version in found in the storage medium  22 . The process proceeds to step P 9  when the suitable version is not found in the storage medium  22 . 
     In step P 8 , the process retrieves the suitable application software and returns to step P 4 . After passing step P 8 , the determination in step P 4  always becomes affirmative (YES), and the process proceeds to step P 5 . 
     In step P 9 , the process displays an error message for notifying a condition that the suitable software is not found in the storage medium  22  due to, for example, a mismatch, an absence of the medium  22  or the software on the medium  22 . The process returns to step P 1  after displaying the error message. 
     In step P 10 , the process performs an end process for ending the navigation process. In this manner, the application software is switched whenever the traveling vehicle causes change of the current region. 
     The navigation system  11  having the operation scheme of the above description is capable of retrieving the application software that is suitable for the current region when the navigation system  11  is turned on, and is capable of switching the application software when required application software is different from the current application software in use due to the travel of the vehicle across the boundary of the current region. Therefore, a single model of the navigation system  11  can be adaptively used in various regions and/or countries by switching the versions of the application software. In addition, manufacturing process of the navigation system  11  is simplified because of the decrease of the number of the models to cover different countries. 
     (Second Embodiment) 
       FIG. 5  shows a flowchart of a control process in a second embodiment of the present disclosure. The description of the second embodiment is focused to a portion of the process that is different from the first embodiment. 
     The second embodiment assumes the travel of the navigation system  11  around the border of the different regions. That is, the travel of the navigation system  11  along a road that frequently crosses the border of the different regions causes a frequent switching of the application software, thereby causing an unstable condition in the navigation system  11 . 
     Therefore, the process in  FIG. 5  has an additional step P 11  after the suitability of the application software is determined in step P 4 . Then, in step P 11 , the process determines whether the vehicle has proceeded for more than A km from the boundary of the region. The process proceeds to step P 7  to switch the application software when the vehicle has proceeded for A km or more from the boundary (step P 11  :YES). The process proceeds to step P 5  when the vehicle stays within the A km from the boundary (step P 1 :NO). In this manner, the control unit  12  stably controls the operation of the navigation system  11  when the vehicle travels along the boundary of the different regions. 
     (Third Embodiment) 
       FIG. 6  shows a flowchart of a control process in a third embodiment of the present disclosure. The difference of the third embodiment from the second one exists in that the process determines whether the vehicle has proceeded B minutes after crossing the boundary. That is, in step P 12 , the process determines a travel time after crossing the boundary of the different regions. The process proceeds to step P 7  when the travel time reaches a predetermined value (step P 12 :YES). The process proceeds to step P 7  when the travel time is less than the predetermined value (step P 12 :NO). 
     In this manner, the control unit  12  can stably controls the operation of the navigation system  11  when the vehicle travels along the boundary of the different regions. 
     Although the present disclosure has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. 
     For example, the application software controlled by the application control system may not only control the map data, but also control information such as travel guide information and/or other additional information. 
     The current position of the vehicle may not necessarily be determined by the GPS signal, but may be detected and determined based on, for example, a signal that conveys positional information provided by an external source. Further, the current position is detected based on an address, a region name or the like. 
     The storage medium  22  may be different from the CD-ROM, the DVD-ROM or the like. That is, the storage medium  22  may be non-volatile memories such as a hard disk device, a flash memory device, or a storage device such as an IC card or the like. Further, the information may be stored in an external storage by using a radio communication or the like. 
     The application control system may also be applicable to a portable information terminal that is carried by a user, or applicable to a system such as a personal computer, a cellular phone or the like. 
     Further, use of a so-called hysteresis function for controlling the switching timing of the application software in the second and third embodiment may be selected by the user. The amount of the hysteresis may also be selected and/or determined by the user for the improved adaptability. 
     Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.