Traffic Information Providing System and Car Navigation System

• US 20110112753A1
• Filed: 01/18/2011
• Published: 05/12/2011
• Est. Priority Date: 10/16/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: YAMANE, Kenichiro, Kumagai, Masatoshi, Endo, Yoshinori, Matsuo, Shigeru, Machii, Kimiyoshi, Yokota, Takayoshi, Fujiwara, Junsuke
• Granted Patent: US 8,068,973 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 car navigation system for receiving information provided by a traffic information providing system, wherein the traffic information providing system comprises:

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;

wherein the car navigation system comprises;

means for acquiring information about the probability that the travel time of the specific route is in the travel time range set by the setting means or the travel time range in which the travel time of the specific route falls in the travel time probability set by the setting means; and

means for displaying the acquired information about the probability that the travel time of the specific route is in the travel time range or the travel time range in which the travel time of the specific route falls in the travel time probability.

2. The car navigation system as set forth in claim 1, 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.

3. The car navigation system as set forth in claim 1, 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.

4. The car navigation system as set forth in claim 2, wherein said predetermined conditions comprise the maximum width of travel time width or the lower limit valve of travel time probability,

when the calculated probability for the travel time range of the specific route set by the setting means lowers than the lower limit value of the travel time probability;

said changing means sets said lower limit value of the travel time probability, sets said lower limit value of the travel time probability as the travel time probability, and when the travel time range for the travel time probability of the specific route set by the setting means extends beyond the travel time width, said changing means sets the upper limit or lower limit of the travel time width as the travel time range.