Traffic Information Providing System and Car Navigation System

• US 20080140308A1
• Filed: 02/07/2008
• Published: 06/12/2008
• Est. Priority Date: 10/16/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kumagai, Masatoshi, Endo, Yoshinori, Matsuo, Shigeru, Machii, Kimiyoshi, Yokota, Takayoshi, Fujiwara, Junsuke, YAMANE, Kenichiro
• Granted Patent: US 7,894,981 B2
• Time in Patent Office: Days
• US Class Current: 701/200
• CPC Class Codes: G01C 21/3492 employing speed data or traffic data, e.g. real-time or historical traffic control systems for road vehicles involving transmission of navigation instructions to the vehicle G08G1/0968
• CPC Class Codes: G08G 1/096827 where the route is computed onboard
• CPC Class Codes: G08G 1/096838 where the user preferences are taken into account or the user selects one route out of a plurality
• CPC Class Codes: G08G 1/096883 where input information is obtained using a mobile device, e.g. a mobile phone, a PDA

Abstract

A traffic information providing system externally acquires traffic information including information relating to the travel time of a link, calculates a travel time for a non-provision link to which no travel time is provided through estimate/complement operation. The estimate/complement operation is carried out with use of travel times, emergencies, travel times of links in the vicinity of the non-provision link, and so on, obtained in the near past. The system stores and statistically processes the externally-acquired traffic information, and also estimates a travel time in the near future. When there is an abnormality in the acquired traffic information, the system deletes the abnormality, regards the information as a non-provision link, calculates a probability distribution of travel times of links, calculates a probability distribution of travel times of the entire route made up of a plurality of links, and also calculates a probability for a specific travel time range.

Claims

1. A traffic information providing system for creating traffic information to be used in a car navigation system, comprising:

traffic information acquiring means for externally acquiring traffic information including information about a travel time of each of links making up a road on a map;

storage means for storing the traffic information acquired by the traffic information acquiring means; and

travel time probability calculating means for calculating a probability distribution of travel times of the links with use of past traffic information stored by the storage means.

2. The traffic information providing system as set forth in claim 1, comprising:

route travel-time probability calculating means for calculating a probability distribution of travel times of a specific route making up a plurality of links with use of the probability distribution calculated by the link travel-time probability calculating means; and

means for calculating a probability for a specific travel time range with use of the probability distribution calculated by the route travel-time probability calculating means.

3. A car navigation system comprising:

means for acquiring information about the probability for the specific travel time range of the specific route created by the traffic information providing system set forth in claim 2 from the traffic information providing system; and

means for displaying information about a probability for the specific travel time range of the acquired specific route.

4. A car navigation system comprising:

means for acquiring information about a probability distribution of travel times of links created by the traffic information providing system set forth in claim 1;

route travel-time probability calculating means for calculating a probability distribution of travel times of a specific route making up a plurality of links with use of the probability distribution of the link travel times;

setting means for setting a travel time range or a travel time probability for the specific routes;

reliability calculating means, when the travel time range of the specific route is set by the setting means, for calculating a probability that the travel time of the specific route is in the travel time range set by the setting means with use of the probability distribution of travel times of the specific route and, when the travel time probability of the specific route is set by the setting means, and for calculating a travel time range in which the travel time of the specific time falls in the travel time probability set by the setting means with use of the probability distribution of travel times of the specific route; and

reliability display means for displaying a result calculated by the reliability calculating means.

5. The car navigation system as set forth in claim 4, comprising a changing means, when the result calculated by the reliability calculating means fails to satisfy predetermined conditions, for changing the travel time range or the travel time probability set by the setting means, and wherein the reliability calculating means has means for regarding the travel time range or the travel time probability changed by the changing means as having set by the setting means and for again performing the calculation.

6. The car navigation system as set forth in claim 4, comprising means, when displaying traffic information about a plurality of the specific routes, for displaying the traffic information in an increasing order of the route travel times or in a decreasing order of the probabilities for the travel time.