Traffic information estimating system

• US 7,536,254 B2
• Filed: 02/17/2006
• Issued: 05/19/2009
• Est. Priority Date: 03/09/2005
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kumagai, Masatoshi, Fushiki, Takumi, Kimita, Kazuya, Yokota, Takayoshi
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Chen; Shelley
• Application Number:
  US11/356,221
• Publication Number:
  US 20060206256A1
• Time in Patent Office: 1,187 Days
• Field of Search: 701117-119
• US Class Current: 701/117
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions

Abstract

A traffic information system includes: a past information database for storing past information, which is collected for road links in a predetermined area, of a past mobile object on a road; a current information database for storing running information, which is collected for the road links in the predetermined area, of a current mobile object; link correlation analyzing means in which correlations of traffic information among each road link in the predetermined area are calculated from the past information stored in the past information database, and output as link correlation information among the road links; combination calculating means for calculating weighting information for obtaining the current information as a sum of the link correlation information; and traffic information estimating means for calculating estimated traffic information for a link where the current information is not collected based on the link correlation information and the weighting information.

Claims

1. A traffic information estimating system, comprising:

a past information database for storing past information, which is collected with respect to any road links in a predetermined area;

a current information database for storing current traffic information with respect to any road links in the predetermined area;

base calculating means for calculating a plurality of bases each of which is correlation information for approximating traffic information of each of the road links in the predetermined area by a linear sum using a plurality of the correlation information among the road links based on the past information stored in the past information database, by using a principal component analysis with missing data;

a weighting coefficient calculating means for calculating a weighting coefficients of each of the bases for approximating the current traffic information which is stored in the current information database by linear sum of the bases; and

a traffic information estimating means for calculating the estimated traffic information for a link where the current traffic information is lacking based on the bases calculated by the base calculating means and the weighting coefficient.

2. The traffic information estimating system according to claim 1,

wherein the base calculating means configures the each base with components which vary with correlations among each link of the road links in the past information.

3. The traffic information estimating system according to claim 1,

wherein the current information is measured at a predetermined time interval;

wherein the weighting coefficient calculating means determines the weighting coefficients of the bases, based on a weighting value depending on freshness of the current information.

4. The traffic information estimating system according to claim 1,

wherein the weighting coefficient calculating means determines the weighting coefficients of the bases, based on a weighting value depending on a degree of a reliability of the current information.

5. The traffic information estimating system according to claim 1,

wherein the weighting coefficient calculating means determines the weighting coefficients of the bases, based on a weighting value depending on a degree of a reliability of the current information,

wherein the degree of the reliability of the current information is defined depending on a number of the mobile objects.

6. The traffic information estimating system according to claim 1, further comprising traffic information estimating means for calculating estimated traffic information which is produced by the linear sum of the bases by using the weighting coefficients as coefficients,

wherein the estimated traffic information is output as complementary traffic information to a road link where the current information is not collected.