Traffic information system

• US 20060206256A1
• Filed: 02/17/2006
• Published: 09/14/2006
• 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
• Granted Patent: US 7,536,254 B2
• Time in Patent Office: Days
• 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 colleted 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 colleted 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 system, comprising:

a past information database for storing past information, which is colleted 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 colleted 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.

2. The traffic information system according to claim 1,

wherein the correlations of traffic information among each road link are bases which are calculated by a principal component analysis with missing data;

wherein the weighting information is weighting coefficient of the base.

3. The traffic information system according to claim 1, further comprising a map database storing connection information of each road link,

wherein the traffic information estimating means outputs complementary traffic information to a road link where the current information is not collected based on the current information, the estimated traffic information, and map information.

4. A traffic information system, comprising:

a past information database for storing past information, which is colleted 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 colleted for the road links in the predetermined area, of a current mobile object;

base calculating means for calculating a plurality of bases which approximate traffic information among each road link in the predetermined area by a linear sum, based on the past information stored in the past information database; and

weighting coefficient calculating means for determining weighting coefficients which are used for combining the bases by the linear sum, based on the current information.

5. The traffic information system according to claim 4,

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.

6. The traffic information system according to claim 4,

wherein the current information is measured with 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.

7. The traffic information system according to claim 4,

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.

8. The traffic information system according to claim 4,

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.

9. The traffic information system according to claim4, 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.