Apparatus and method for generating statistic traffic information

• US 8,405,521 B2
• Filed: 06/25/2010
• Issued: 03/26/2013
• Est. Priority Date: 06/26/2009
• Status: Active Grant

• Current Assignee: Clarion Co., Ltd. (Faurecia SA)
• Original Assignee: Clarion Co., Ltd. (Faurecia SA)
• Inventors: Fujiwara, Junsuke, Fushiki, Takumi
• Primary Examiner(s): Phan, Hai
• Assistant Examiner(s): NWUGO, OJIAKO K
• Application Number:
  US12/823,717
• Publication Number:
  US 20100328100A1
• Time in Patent Office: 1,005 Days
• Field of Search: 340933-938, 3409951-99528, 701117-119, 701409-471
• US Class Current: 340/905
• CPC Class Codes: G08G 1/0112 from the vehicle, e.g. floating car data [FCD]
• CPC Class Codes: G08G 1/0129 for creating historical data or processing based on historical data
• CPC Class Codes: G08G 1/0141 for traffic information dissemination

Abstract

A statistic DB creation processing section creates a statistic traffic DB, based on past actual traffic data (probe DB or VICS DB), and stores it in a statistic DB storage section. A reference-link-candidate extraction processing section extracts a complement target link (temporal missing link) from the statistic traffic DB, and further extracts complementary-reference-link-candidates for the complement target link, according to plural extraction rules to extract complementary-reference-link-candidates. A complement-evaluation application processing section calculates correlation coefficients of the statistic traffic data of the complementary-reference-link-candidates to the statistic traffic data of the complement target link for the respective extraction rules, assigns a priority order to the extraction rules in the order of higher correlation coefficient, and complements the missing data of the statistic traffic data of the complement target link by the use of the statistic traffic data of the complementary reference link extracted by the extraction rule of the highest priority.

Claims

1. A statistic traffic information generating apparatus, comprising:

a statistic traffic data storage unit that stores statistic traffic data associated with road links;

a missing link extraction unit that extracts a missing link whose statistic traffic data is partially missing from the statistic traffic data storage unit;

a complement rule storage unit that stores complement rules associated with an extraction of a complementary road link to be used to complement a missing part of the statistic traffic data of the missing link;

a candidate link extraction unit that extracts candidate links to be candidates of the complementary road link extracted by the extraction unit, according to the complement rules stored in the complement rule storage unit;

a calculation unit that calculates a degree of similarity between the statistic traffic data of the missing link extracted by the missing link extraction unit and the statistic data of the candidate links extracted by the candidate link extraction unit, for the respective complement rules stored in the complement rule storage unit;

a priority order assignment unit that assigns a priority order to the complement rules stored in the complement rule storage unit, according to the degree of similarity calculated by the calculation unit;

a complementary link extraction unit that extracts the complementary link for complement of the missing statistic traffic data, using a complement rule based on the priority order assigned by the priority order assignment unit; and

a complement unit that complements the missing part of the statistic traffic data in the statistic traffic data of the missing link extracted by the missing link extraction unit, using the statistic traffic data of the complementary link extracted by the complementary link extraction unit.

2. The statistic traffic information generating apparatus according to claim 1,

wherein the calculation unit comprises a sorting unit that sorts the statistic traffic data, using at least one item of day type and time sectioning that divides one day into plural time zones,

wherein the calculation unit calculates the degree of similarity for the respective statistic traffic data sorted by the sorting unit.

3. The statistic traffic information generating apparatus according to claim 1,

wherein the calculation unit comprises:

an average traffic data calculation unit that calculates an average traffic data of the statistic traffic data of the candidate links, more than one of which is extracted by the candidate link extraction unit in each of the complement rules;

a correlation coefficient calculation unit that calculates a correlation coefficient between the statistic traffic data of a significant part of the missing link and the average traffic data calculated by the average traffic data calculation unit in each of the complement rules; and

a relative error calculation unit that calculates relative errors between the average traffic data calculated by the average traffic data calculation unit and the statistic traffic data of a significant part of the missing link, and calculates inverses of the respective relative errors, for the respective complement rules stored in the complement rule storage unit,

wherein the calculation unit calculates the degree of similarity, based on a value of either the correlation coefficient calculated by the correlation coefficient calculation unit or the inverses of the relative errors calculated by the relative error calculation unit.

4. The statistic traffic information generating apparatus according to claim 1, further comprising:

a congestion frequency calculation unit that calculates a congestion frequency for each road link, based on the statistic traffic data associated with the road link;

a bottleneck identification unit that identifies a bottleneck connection point between road links connected with each other, using the congestion frequency calculated by the congestion frequency calculation unit; and

a filtering unit that eliminates

an outflow link at the connection point identified by the bottleneck identification unit in a case where the missing link extracted by the missing link extraction unit is an inflow link, or

an inflow link at the connection point identified by the bottleneck identification unit in a case where the missing link extracted by the missing link extraction unit is an outflow link,

from a candidate link extracted by the candidate link extraction unit, with respect to the connection points of the road links identified by the bottleneck identification unit.

5. A method of generating statistic traffic information, comprising:

a statistic traffic data storage process that stores statistic traffic data associated with road links;

a missing link extraction process that extracts a missing link whose statistic traffic data is partially missing from the statistic traffic data storage process;

a complement rule storage process that stores complement rules associated with an extraction of a complementary link to be used to complement a missing part of the statistic traffic data of the missing link;

a candidate link extraction process that extracts candidate links to be candidates of the complement link, according to the complement rules stored in a complement rule storage unit;

a calculation process that calculates a degree of similarity between the statistic traffic data of the missing link extracted by the missing link extraction process and the statistic data of the candidate links being extracted by the candidate link extraction process, for the respective complement rules stored in the complement rule storage unit;

a priority order assignment process that assigns a priority order to the complement rules stored in the complement rule storage unit, according to the degree of similarity calculated by the calculation process;

a complementary link extraction process that extracts the complementary link for complement of the missing statistic traffic data, using a complement rule based on the priority order assigned by the priority order assignment process; and

a complement process that complements the missing part of the statistic traffic data in the statistic traffic data of the missing link extracted by the missing link extraction process, using the statistic traffic data of the complementary link extracted by the complementary link extraction process.

6. The method of generating statistic traffic information according to claim 5,

wherein the calculation process performs:

a sorting process that sorts the statistic traffic data, using at least one item of day type and time-sectioning that divides one day into plural time zones; and

a calculation process that calculates the degree of similarity for the respective statistic traffic data sorted by the sorting process.

7. The method of generating statistic traffic information according to claim 5,

wherein the calculation process performs:

an average traffic data calculation process that calculates an average traffic data of the statistic traffic data of the candidate links, more than one of which is extracted by the candidate link extraction process in each of the complement rules;

a correlation coefficient calculation process that calculates a correlation coefficient between the statistic traffic data of a significant part of the missing link extracted by the complementary link extraction process and the average value calculated by the average value calculation unit; and

a relative error calculation process that calculates relative errors between the average traffic data calculated by the average traffic data calculation process and the statistic traffic data of a significant part of the missing link, and calculates inverses of the respective relative errors, for the respective complement rules stored in the complement rule storage unit; and

a process that calculates the degree of similarity, based on a value of either the correlation coefficient calculated by the correlation coefficient calculation process or the inverses of the respective relative errors calculated by the relative error calculation process.

8. The method of generating statistic traffic information according to claim 5, further comprising:

a congestion frequency calculation process that calculates a congestion frequency for each road link, based on the statistic traffic data associated with the road link;

a bottleneck identification process that identifies a bottleneck connection point between road links connected with each other, using the congestion frequency calculated by the congestion frequency calculation process; and

a filtering process that eliminates

an outflow link at the connection point identified by the bottleneck identification process in a case where the missing link by the extraction process is an inflow link, or

an inflow link at the connection point identified by the bottleneck identification process in a case where the missing link extracted by the missing link extraction process is an outflow link,

from a candidate link extracted by the candidate link extraction process, with respect to the connection points of the road links identified by the bottleneck identification process.