Traffic information providing system and car navigation system

• US 7,894,981 B2
• Filed: 02/07/2008
• Issued: 02/22/2011
• Est. Priority Date: 10/16/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kumagai, Masatoshi, Endo, Yoshinori, Matsuo, Shigeru, Yamane, Kenichiro, Machii, Kimiyoshi, Yokota, Takayoshi, Fujiwara, Junsuke
• Primary Examiner(s): Nguyen; Cuong H
• Application Number:
  US12/027,433
• Publication Number:
  US 20080140308A1
• Time in Patent Office: 1,111 Days
• Field of Search: 701117-119, 701/202, 701209-210, 340/995.13, 340/995.1
• US Class Current: 701/118
• 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 statistical traffic information, comprising:

storage mage for storing the traffic information including information about a travel time of each of link making up a road on a map, wherein said traffic information being externally acquired by the traffic information acquiring means;

link travel time probability calculating means for calculating a probability distribution of travel times of the links for each time zone with use of past traffic information stored by the storage means every time zone in which the statistical traffic information is created;

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;

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

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, for calculating a travel time range in which the travel time probability set by the setting means with use of the probability distribution of travel times of the specific route.

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

travel 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;

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

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;

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

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