To many Vehicle Navigation users, "Map data update" is one of the big issues.
To get to the "right destination" by the "appropriate route", it is always necessary to keep their map data the latest.
However, since the conventional map update methods that a user would buy DVD/CD media and make whole map data update or user would carry a vehicle navigation system into a dealer shop to rewrite map data of HDD, make those users spend time and effort on, the technology to update only a necessary part of map efficiently has been expected to be developed.
These user needs and expectation to map data update are common to the user who uses the digital map with not only the vehicle navigation system but also all information terminal devices.
Hitachi has newly developed "Incremental Map Update technology" in order to respond to these needs and offers the Integrated Digital Map Solution to support overall management of digital maps used with a wide-variety of information terminals including vehicle navigation system based on this technology.
In detail, Hitachi realizes the compilation process of digital map data provided from the original map vender into the map data format of incremental update, and provide the management service for delivering the incremental update data of digital map to various information terminal devices.
Through these activities, Hitachi aims to obtain the worldwide customers' satisfaction with responding to a lot of customers' needs.
Hitachi also makes continuous effort to promote the development of the map data format for the worldwide market, to create the map update scheme and to achieve a wide adoption, including to aim at de facto standardization with open stance by using the technology and know-how accumulated until now.
The incremental map update is a method of updating "Only part with the change" to make the map data of the information terminal device that uses digital maps such as vehicle navigation system, PND, mobile phone and so on, the latest.
In conventional methods, it is necessary to rewrite a large amount of data by using a large volume media such as DVD to make the map data the latest. While in the new method, by extracting and delivering the minimal data for updating, it becomes available to keep the map data the latest at any time via the Internet or mobile phone, etc.
In the map update of the vehicle navigation system, the most important issue is to update its map data "by ensuring road connection of all roads".
In detail, in case that a road has been changed, the surrounding roads which have the connection to the actually changed road also should be renewed at the same time, otherwise the road connections will be lost, and then the navigation system can not perform the important function such as the route guidance, etc. anymore.
In order to keep the road connection, with the conventional management method of map update using the unit of the "Parcel; rectangular area", it will happen to update the roads without change existing in that Parcel and then to lead to an increase in volume of data. Also, unnecessary updates of Parcel may happen surrounding that Parcel with the changed road in order not to lose the connections of roads. Furthermore, once the surrounding Parcel is involved to update process, the updated road in that Parcel affects to make another update, and again and again, thus successive chain-updates, not necessary essentially, may occur at plural Parcels which have no road should be updated, and may happen to lead to extreme increase in volume of data.
With Hitachi Incremental Map Update technology, the map data itself is managed by the unit of Parcel, however the incremental map update data is extracted by the unit of road as an object. The minimum set of objects which have the relation each other are united exceeding the frame of the Parcel. The set of this object is called "Update element" used as a unit of management of incremental update. As a result, "to ensure road connectivity" and "to minimize the update volume of data" are achieved at the same time.
By adopting the embedded type Relational Data Base(RDB) technology that can manage flexible combination of updating unit of data and update control, wide selection of update size of area and update method are available according to the purpose and its usage.
Moreover, the advanced data management such as recovery function from power failure or other malfunction occur during map data updates, etc. has been achieved.
< Example of Update method and area of Digital map data >
The Integrated Digital Map Solution is consist of the following services.
The compilation service of digital map from the existing map format into the map format using the incremental update technology, with which the Information terminal device can accept the update data delivered from the Map data Distribution Management service.
< Process flow of the Digital Map Compilation service >
The map update data using the incremental map update format is distributed from Hitachi digital map compilation and distribution management center to the information terminal devices via their service provider.
< Example of Update method and area of Digital map data >
A variety of operation support is available when the map format for the incremental update is Introduced.
< Example of the Outsourcing service >
Japan, North America/Mexico, Europe/Russia, the Middle East, South Africa, Australia, etc.
