Apparatus and method for processing and displaying traffic information in an automotive navigation system

• US 7,289,039 B2
• Filed: 03/23/2006
• Issued: 10/30/2007
• Est. Priority Date: 09/10/2004
• Status: Expired due to Fees

• Current Assignee: AutoNavigare LLC
• Original Assignee: Xanavi Informatics Corporation (Hitachi, Ltd.)
• Inventors: Kato, Manabu, Ramaswamy, Deepak, Horiguchi, Sadanori
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): BLOUNT, ERIC
• Application Number:
  US11/387,485
• Publication Number:
  US 20060178807A1
• Time in Patent Office: 586 Days
• Field of Search: 340/995.1
• US Class Current: 340/905
• CPC Class Codes: B60R 11/04 Mounting of cameras operative during drive; Arrangement of controls thereof relative to the vehicle
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• CPC Class Codes: G08G 1/0962 having an indicator mounted inside the vehicle, e.g. giving voice messages
• CPC Class Codes: G08G 1/096716 where the received information does not generate an automatic action on the vehicle control
• CPC Class Codes: G08G 1/096741 where the source of the transmitted information selects which information to transmit to each vehicle
• CPC Class Codes: G08G 1/09675 where a selection from the received information takes place in the vehicle
• CPC Class Codes: G08G 1/096775 where the origin of the information is a central station
• CPC Class Codes: G08G 1/096827 where the route is computed onboard
• CPC Class Codes: G08G 1/096838 where the user preferences are taken into account or the user selects one route out of a plurality
• CPC Class Codes: G08G 1/09685 where the complete route is computed only once and not updated
• CPC Class Codes: G08G 1/096894 where input is assisted by the navigation device, i.e. the user does not type the complete name of the destination, e.g. using zip codes, telephone numbers, progressively selecting from initial letters

Abstract

A vehicle navigation system for use with a traffic information broadcast system which transmits traffic data relating to primary road segments and a communication system which transmits traffic data relating to road segments in a local geographic area. A broadcast receiver receives the broadcast traffic data from the broadcast system and stores the received data. A communication transmitter, when activated, transmits a data request to the communication system. A communication receiver receives the local traffic data from the communication system in response to the data request while a processor displays traffic information on a display screen corresponding to the received broadcast traffic data and the received local traffic data. The local traffic data includes both traffic information relating to local road segments as well as non-traffic temporal events, such as weather, and time-related events which affect traffic flow. A database of historic traffic flow for the road segments is periodically updated to reflect new traffic data.

Claims

1. A method for maintaining road segment data in a vehicle navigation system comprising the steps of:

creating a historic traffic flow database containing traffic flow data for the road segments,

receiving current road segment traffic flow data,

storing said received data in a current traffic flow database,

periodically updating the historic traffic flow database for each road segment by calculating traffic flow data for each road segment as a function of said historic traffic flow database data and said current traffic flow database data, by determining the average speed for the road segment, and determining the statistical variance for the road segment; and

thereafter replacing the historic traffic flow database data with the calculated traffic flow data.

2. The invention as defined in claim 1 and further comprising the step of deleting data from the current traffic flow database following said replacing step.

3. The invention as defined in claim 1 wherein the historic database contains a plurality of road segments, the average speed for each road segment and the statistical population and variance for each said road segment.

4. The invention as defined in claim 3 wherein said updating step updates the average speed, statistical population and statistical variance for at least one road segment.

5. The invention as defined in claim 1 wherein said periodically updating step comprises the steps of:

storing the time of the last periodic update,

determining the time span between the current time and the stored time of the last periodic update, and

updating the statistical database only when the time span exceeds a predetermined time period.

6. Apparatus for maintaining road segment data in a vehicle navigation system comprising:

means for creating a historic traffic flow database containing traffic flow data for the road segments,

means for receiving current road segment traffic flow data,

means for storing said received data in a current traffic flow database,

means for periodically updating the historic traffic flow database for each road segment by calculating traffic flow data for each road segment as a function of said historic traffic flow database data and said current traffic flow database data, by means for determining the average speed for the road segment, and means for determining the statistical variance for the road segment; and

means for thereafter replacing the historic traffic flow database data with the calculated traffic flow data.

7. The invention as defined in claim 6 and further comprising means for deleting data from the current traffic flow database following the replacement of the historic traffic flow database with the calculated traffic flow data.

8. The invention as defined in claim 6 wherein the historic database contains a plurality of road segments, the average speed for each road segment and the statistical population and variance for each said road segment.

9. The invention as defined in claim 8 wherein said updating means comprises means for updating the average speed, statistical population and statistical variance for at least one road segment.

10. The invention as defined in claim 6 wherein said periodically updating means comprises:

means for storing the time of the last periodic update,

means for determining the time span between the current time and the stored time of the last periodic update, and

means for updating the statistical database only when the time span exceeds a predetermined time period.

11. A method for maintaining road segment traffic flow data in a vehicle navigation system comprising the steps of:

maintaining a statistical traffic flow database for at least one road segment,

obtaining real time traffic data for said at least one road segment,

comparing said real time traffic data with statistical data for said at least one road segment,

generating a request to a traffic server when the difference between said real-time traffic data and said statistical database exceeds a predetermined amount,

obtaining statistical traffic data for said at least one road segment from said traffic server, and

storing said received data in said statistical traffic flow database.

12. The invention as defined in claim 11 wherein said statistical traffic flow database comprises a plurality of road segments, an average speed for each road segment and the statistical population and variance for each road segment.

13. Apparatus for maintaining road segment data in a vehicle navigation system comprising:

means for maintaining a statistical traffic flow database for at least one road segment,

means for obtaining real-time traffic data for said at least one road segment,

means for comparing said real-time traffic data with statistical data for said at least one road segment,

means for generating a request to a traffic server when the difference between said real-time traffic data and said statistical database exceeds a predetermined amount,

means for obtaining statistical traffic data for said at least one road segment from said traffic server, and

means for storing said received data in said statistical traffic flow database.

14. The invention as defined in claim 13 wherein said statistical traffic flow database comprises a plurality of road segments, an average speed for each road segment and the statistical population and variance for each road segment.

15. The invention as defined in claim 14 wherein said storing means stores the average speed, statistical variance and statistical population for each road segment.