Patent ID: 9127954
Filing Date: 2015-09-08
Classification: G01C,G08G,G09B

Abstract:
1. A navigation system comprising: a navigation apparatus that performs a route guidance, the navigation apparatus storing map data including a plurality of segment data elements, the map data being indicative of a map of an area, each of the plurality of segment data elements being indicative of a corresponding segment included in the area; a data center that performs a data communication with the navigation apparatus to transmit update data of a target region, which is included in the area, to the navigation apparatus, the target region including one or more target segments whose segment data elements are to be updated by the update data, the update data of the target region being transmitted per segment data element; a communication-defective region acquisition device that acquires information of a communication-defective region, the communication-defective region being included in the area and being defined as a region where the data communication becomes defective; a communication-defective region search device that, every time a vehicle travels across two adjacent segments of the area, searches in real time for a part of the communication-defective region as a target communication-defective region, which includes a route scheduled to go through; and a target region specify device that, every time the vehicle travels across the two adjacent segments of the area, specifies in real time the target region based on the target communication-defective region, wherein, the data center includes an update data transmission device that transmits the update data of the target region to the navigation apparatus before the navigation apparatus enters the target communication-defective region, the target region specify device specifies the target region in such a manner that the target region includes the target communication-defective region, the communication-defective region search device sets, without depending on a preset guidance route, and based on a travelling direction and a present position of the vehicle, at least a part of a predetermined area, which includes a road ahead in the travelling direction, as the route scheduled to go through, and the target region specify device specifies, without depending on a preset guidance route, the target region in such a manner that the target region includes the at least a part of the predetermined area set based on the travelling direction and the present position of the vehicle.