Apparatus and Method for Generating Statistic Traffic Information

• US 20100328100A1
• Filed: 06/25/2010
• Published: 12/30/2010
• 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
• Granted Patent: US 8,405,521 B2
• Time in Patent Office: Days
• 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 storage unit that stores statistic traffic data corresponding to road links;

an extraction unit that detects a road link whose statistic traffic data is partially missing;

a complement rule storage unit that stores complement rules to adopt a road link corresponding to statistic traffic data to be used to complement the missing statistic traffic data;

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

a calculation unit that calculates similarities between the road link extracted by the extraction unit and the respective road links of candidates for complement, for the respective complement rules stored in the complement rule storage unit, the candidates being extracted by the candidate link extraction 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 similarities calculated by the calculation unit;

a complementary link extraction unit that extracts a 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 statistic traffic data in the statistic traffic data that corresponds to the road link extracted by the extraction unit, using statistic traffic data that corresponds to the 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 lease one item of day type and time sectioning that divides one day into plural time zones,

wherein the calculation unit calculates the similarities 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 value calculation unit that calculates an average value of the statistic traffic data corresponding to the road link extracted by the complementary link extraction unit;

a correlation coefficient calculation unit that calculates a correlation coefficient between the statistic traffic data corresponding to the road link extracted by the complementary link extraction unit and the average value calculated by the average value calculation unit; and

a relative error calculation unit that calculates relative errors between the average value calculated by the average value calculation unit and the statistic traffic data corresponding to the road link extracted by the extraction unit, 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 similarities, 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 corresponding to 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 road link detected by the 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 road link detected by the extraction unit is an outflow link,

from the road links 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:

an extraction process that stores statistic traffic data corresponding to road links into a storage unit, and detects a road link whose stored statistic traffic data is partially missing;

a candidate link extraction process that extracts links to be candidates that complement the road link extracted by the extraction process, according to complement rules to adopt a road link corresponding to statistic traffic data to be used to complement the missing statistic traffic data, the complement rules being stored in a complement rule storage unit;

a calculation process that calculates similarities between the road link extracted by the extraction process and the respective road links of candidates for complement, for the respective complement rules stored in the complement rule storage unit, the candidates being extracted by the candidate link extraction process;

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

a complementary link extraction process that extracts a 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 statistic traffic data in the statistic traffic data that corresponds to the road link extracted by the extraction process, using statistic traffic data that corresponds to the 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 lease one item of day type and time-sectioning that divides one day into plural time zones; and

a calculation process that calculates the similarities 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 value calculation process that calculates an average value of the statistic traffic data corresponding to the road link extracted by the complementary link extraction process;

a correlation coefficient calculation process that calculates a correlation coefficient between the statistic traffic data corresponding to the road 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 value calculated by the average value calculation process and the statistic traffic data corresponding to the road link extracted by the extraction process, 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 similarities, 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 corresponding to 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 road link detected 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 road link detected by the extraction process is an outflow link,

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