Road congestion detection by distributed vehicle-to-vehicle communication systems

• US 20080059050A1
• Filed: 02/28/2007
• Published: 03/06/2008
• Est. Priority Date: 08/31/2006
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Osafune, Tatsuaki, Lin, Lan
• Granted Patent: US 7,877,196 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

The present invention relates to a method and apparatus for determining traffic condition comprising the steps of determining periodically a position data of a host vehicle 1, wherein the position data includes a time stamp, position, velocity and driving direction of the host vehicle 1, receiving periodically position data of at least an other vehicle 2, 3, 4, wherein the position data includes a time stamp, position, velocity and driving direction of the other vehicle 2, 3, 4, storing the position data of the host vehicle 1 and the position data of at least the other vehicle 2, 3, 4, calculating a relative position data, wherein the relative position data includes relative velocity and relative driving direction between the host vehicle 1 and the other vehicle 2, 3, 4, and judging a traffic condition based on the position data of the host vehicle 1, the position data of the other vehicle 2, 3, 4 and the relative position data.

Claims

1. Method for determining traffic condition comprising the steps of:

determining periodically a position data of a host vehicle (1), wherein the position data includes a time stamp, position, velocity and driving direction of the host vehicle (1),

receiving periodically position data of at least an other vehicle (2, 3, 4), wherein the position data includes a time stamp, position, velocity and driving direction of the other vehicle (2, 3, 4),

storing the position data of the host vehicle (1) and the position data of at least the other vehicle (2, 3, 4),

calculating a relative position data, wherein the relative position data includes relative velocity and relative driving direction between the host vehicle (1) and the other vehicle (2, 3, 4), and

judging a traffic condition based on the position data of the host vehicle (1), the position data of the other vehicle (2, 3, 4) and the relative position data.

2. Method according to claim 1, wherein

the position data of the other vehicle (2, 3, 4) is discarded when the angle of the relative direction between the host vehicle (1) and the other vehicle (2, 3, 4) is larger than a predetermined angle.

3. Method according to claim 1 or 2, wherein

the position data of the other vehicle (2, 3, 4) is discarded when the time interval between the timestamp of the other vehicle (2, 3, 4) and the actual time is larger than a predetermined period.

4. Method according to at least one of claims 1 to 3, wherein

based on the position data of the host vehicle (1) a traffic jam estimation value is determined and based on the relative position data between the host vehicle (1) and the other vehicle (2, 3, 4) a relative traffic jam estimation value is determined.

5. Method according to at least one of the preceding claims, wherein

based on the relative position data, the traffic jam estimation value and the relative traffic jam estimation value are weighted.

6. Method according to at least one of the preceding claims, wherein

based on the traffic jam estimation value and the relative traffic jam estimation value a voting jam value is determined.

7. Method according to claim 6, wherein

based on the voting jam value a voting request message is broadcasted by the host vehicle (1).

8. Method according to at least one of the preceding claims, wherein

the other vehicle (2, 3, 4) broadcasts a voting reply message as response to the voting request message of the host vehicle (1).

9. Method according to at least one of the preceding claims, wherein

based on the voting request message and the voting reply messages received by the host vehicle (1) the traffic condition is determined.

10. Method according to at least one of the preceding claims, wherein

based on the voting request message and the voting reply messages the position of the host vehicle (1) in respect to the traffic condition is determined.

11. Method according to at least one of the preceding claims, wherein

based on the position of the host vehicle (1) in respect to the traffic condition a corresponding traffic condition message is broadcasted.

12. Apparatus for determining traffic condition comprising:

a position determining (10) means for periodically determining a position data of a host vehicle (1), wherein the position data includes a time stamp, position, velocity and driving direction of the host vehicle (1),

a receiving means (11) for periodically receiving position data of at least an other vehicle (2, 3, 4), wherein the position data includes a time stamp, position, velocity and driving direction of the other vehicle (2, 3, 4),

a storing means (12) for storing the position data of the host vehicle (1) and the position data of at least the other vehicle (2, 3, 4),

a relative position calculating means (13) calculating a relative position data, wherein the relative position data includes relative velocity and relative driving direction between the host vehicle (1) and the other vehicle (2, 3, 4), and

a traffic condition judging (14) means for judging the traffic condition based on the position data of the host vehicle (1), the position data of the other vehicle (2, 3, 4) and the relative position data.

13. Apparatus according to claim 12, wherein

a discarding means (15) discards the position data of the other vehicle (2, 3, 4) when the angle of the relative direction between the host vehicle (1) and the other vehicle (2, 3, 4) is larger than a predetermined angle.

14. Apparatus according to claim 12 or 13, wherein

the discarding means discards the position data of the other vehicle (2, 3, 4) when time interval between the timestamp of the other vehicle (2, 3, 4) and the other vehicle (2, 3, 4) and the actual time is larger than a predetermined period.

15. Apparatus according to at least one of claims 12 to 14, wherein

a traffic jam estimation value means (16) determines a traffic jam estimation value based on the position data of the host vehicle (1) and a relative traffic jam estimation value based on the relative position data between the host vehicle (1) and the other vehicle (2, 3, 4).

16. Apparatus according to at least one of claims 12 to 15, wherein

a weighting means (17) determines a weighting factor based on the relative position data, the traffic jam estimation value and the relative traffic jam estimation value.

17. Apparatus according to at least one of claims 12 to 16, wherein

a voting jam determining value means determines a voting jam value based on the traffic jam estimation value and the relative traffic jam estimation value.

18. Apparatus according to at least one of claims 12 to 17, wherein

a broadcasting means (18) broadcasts a voting request message of the host vehicle (1) based on the voting jam value or a voting reply message of the other vehicle (2, 3, 4).

19. Apparatus according to at least one of claims 12 to 17, wherein

the receiving means (11) receives a voting reply message from the other vehicle (2, 3, 4) or a voting request message from the host vehicle (1).

20. Apparatus according to at least one of claims 12 to 17, wherein

a timer setup means (19) sets up a timer to generate the reply message at the other vehicle (2, 3, 4) side or to collect the reply messages at the host vehicle (1) side.

21. Apparatus according to at least one of claims 12 to 20, wherein

a traffic condition determining means (21) determines a traffic condition based on the voting request message and at least one received voting reply message.

22. Apparatus according to at least one of claims 12 to 21, wherein

the position determining means (10) determines the position of the host vehicle (1) in respect to the traffic condition based on the voting request message and the voting reply message.

23. Apparatus according to at least one of claims 12 to 22, wherein

the broadcasting means (18) broadcasts a corresponding traffic condition message based on the position of the host vehicle (1) in respect to the traffic condition.