Method and system for route searching, and navigation apparatus using the same

• US 8,255,162 B2
• Filed: 08/07/2008
• Issued: 08/28/2012
• Est. Priority Date: 08/08/2007
• Status: Active Grant

• Current Assignee: AutoNavigare LLC
• Original Assignee: Xanavi Informatics Corporation (Hitachi, Ltd.)
• Inventors: Okude, Mariko, Kumagai, Masatoshi, Fushiki, Takumi, Tanikoshi, Koichiro
• Primary Examiner(s): ALMATRAHI, FARIS S
• Application Number:
  US12/188,040
• Publication Number:
  US 20090048775A1
• Time in Patent Office: 1,482 Days
• Field of Search: None
• US Class Current: 701/533
• CPC Class Codes: G01C 21/3446 Details of route searching algorithms, e.g. Dijkstra, A*, arc-flags, using precalculated routes
• CPC Class Codes: G01C 21/3484 Personalized, e.g. from learned user behaviour or user-defined profiles

Abstract

A route searching method is provided which allows drivers having mutually similar traveling purposes and preferences to find highly convenient routes by sharing their route searching know-how. A center apparatus (1) collects probe data received from an in-vehicle terminal apparatus (5). A preference parameter creating unit (14) calculates, based on the probe data, road usage frequencies according to preference items such as vehicle type, driver age and gender, and travel purpose which can be factors for route selection and stores the calculated road usage frequencies as preference parameters in a preference parameter database (15). A route searching unit (513) included in the in-vehicle terminal apparatus (5) requests the center apparatus (1) to transmit a preference parameter similar to user attribute information (519), adjusts link costs according to the preference parameter received from the center apparatus, and determines a minimum-cost route to a destination.

Claims

1. A route searching method for execution by a computer for finding a recommended route from a departure place to a destination,

wherein the computer stores preference parameters calculated as usage frequencies of preference items by using probe data collected from a plurality of vehicles,

wherein each usage frequency is a ratio of a number of travel counts of the respective preference item for a road link to a number of total travel counts for the road link, and

wherein the computer executes the steps of:

receiving location information specifying a departure place and a destination;

selecting, out of the preference parameters, at least one preference parameter similar to user attribute data;

adjusting, based on the selected preference parameter, a cost of each road link such that the cost decreases as a match between the selected preference parameter and a user'"'"'s preference increases; and

determining, based on the adjusted cost of each road link, a minimum-cost route from a departure place to a destination.

2. The route searching method according to claim 1,

wherein the preference items comprise information which can be factors for route selection on such items as vehicle type, driver age, driver gender, travel purpose, and passengers, and

wherein the user attribute data comprises information which indicate characteristics of a user or vehicle on such items as vehicle type, driver age, driver gender, travel purpose, and passengers.

3. The route searching method according to claim 1, wherein the step of selecting, out of the preference parameters, at least one preference parameter similar to user attribute data includes the steps of:

determining, based on user vehicle travel data, a route preference of the user; and

selecting, out of the preference parameters, at least one preference parameter similar to the route preference of the user.

4. A route searching system for finding a recommended route from a departure place to a destination, comprising:

an in-vehicle terminal apparatus which transmits travel data as probe data, the travel data including location information, time information, vehicle information such as information on brake and wiper operations, and travel environment information such as atmospheric temperature and road surface temperature information, and

a center apparatus provided with a probe data storing unit which stores the probe data transmitted from the in-vehicle terminal apparatus,

wherein the center apparatus includes;

a preference parameter calculation unit which calculates preference parameters as usage frequencies of preference items by using probe data collected from a plurality of vehicles, wherein each usage frequency is a ratio of a number of travel counts of the respective preference item for a road link to a number of total travel counts for the road link; and

a communication unit which transmits the preference parameters when requested from the in-vehicle terminal apparatus, and

wherein the in-vehicle terminal apparatus includes;

a location information input unit which receives location information specifying a departure place and a destination;

an attribute information storing unit which stores attribute information on such items as vehicle, driver, and passenger;

a communication unit which requests the center apparatus to transmit at least one preference parameter similar to the attribute information and receives the transmitted preference parameter;

a link cost adjusting unit which adjusts a cost of each link according to the received preference parameter such that the cost decreases as a match between the received preference parameter and a user'"'"'s preference increases;

a route searching unit which determines, based on the adjusted link cost, a minimum-cost route from a departure place to a destination; and

a route presentation unit which presents, using a display device or by voice, route information obtained using the route searching unit to the user.

5. The route searching system according to claim 4, wherein the center apparatus further includes a preference parameter consolidation unit which consolidates correlated ones of the preference parameters into a consolidated preference parameter.

6. A route searching system for finding a recommended route from a departure place to a destination, comprising:

an in-vehicle terminal apparatus which transmits travel data as probe data, the travel data including location information, time information, vehicle information such as information on brake and wiper operations, and travel environment information such as atmospheric temperature and road surface temperature information, and

a center apparatus provided with a probe data storing unit which stores the probe data transmitted from the in-vehicle terminal apparatus,

wherein the center apparatus includes;

a preference parameter calculation unit which calculates preference parameters as usage frequencies of preference items by using probe data collected from a plurality of vehicles, wherein each usage frequency is a ratio of a number of travel counts of the respective preference item for a road link to a number of total travel counts for the road link;

a preference parameter storing unit which stores the calculated preference parameters;

a request receiving unit which receives a request for route searching from the in-vehicle terminal apparatus, the request including attribute information on such items as vehicle, driver, and passenger and location information specifying a departure place and a destination;

a route searching unit which selects at least one preference parameter similar to the collected attribute information from the preference parameter storing unit, adjusts costs of links to be considered in route searching according to the selected preference parameter such that the cost decreases as a match between the selected preference parameter and a user'"'"'s preference increases, and determines a minimum-cost route from a departure place to a destination; and

a transmission unit which transmits information on the determined route to the in-vehicle terminal apparatus, and

wherein the in-vehicle terminal apparatus includes;

a location information input unit which receives location information specifying a departure place and a destination;

an attribute information storing unit which stores attribute information on such items as vehicle, driver, and passenger;

a route request unit which requests the center apparatus to search for a route to a destination;

a receiving unit which receives route information from the center apparatus; and

a route presentation unit which presents, using a display device or by voice, the received route information to the user.

7. A route searching system for finding a recommended route from a departure place to a destination, comprising:

an in-vehicle terminal apparatus which transmits travel data as probe data, the travel data including location information, time information, vehicle information such as information on brake and wiper operations, and travel environment information such as atmospheric temperature and road surface temperature information, and

a center apparatus provided with a probe data storing unit which stores the probe data transmitted from the in-vehicle terminal apparatus,

wherein the center apparatus includes;

a preference parameter calculation unit which calculates preference parameters as usage frequencies of preference items by using probe data collected from a plurality of vehicles, wherein each usage frequency is a ratio of a number of travel counts of the respective preference item for a road link to a number of total travel counts for the road link;

a preference parameter storing unit which stores the preference parameters;

a request receiving unit which receives a request for route searching from the in-vehicle terminal apparatus, the request including location information specifying a departure place and a destination;

a route preference calculation unit which determines a route preference of the vehicle based on the travel data stored in the probe data storing unit;

a route searching unit which selects at least one preference parameter similar to the route preference of the vehicle from the preference parameter storing unit, adjusts costs of links to be considered in route searching according to the selected preference parameter such that a cost decreases as a match between the selected preference parameter and a user'"'"'s preference increases, and determines a minimum-cost route from a departure place to a destination; and

a transmission unit which transmits information on the determined route to the in-vehicle terminal apparatus, and

wherein the in-vehicle terminal apparatus includes;

a location information input unit which receives location information specifying a departure place and a destination;

an attribute information storing unit which stores attribute information on such items as vehicle, driver, and passenger;

a route request unit which requests the center apparatus to search for a route to a destination;

a receiving unit which receives route information from the center apparatus; and

a route presentation unit which presents, using a display device or by voice, the received route information to the user.

8. A navigation apparatus for finding a recommended route from a departure place to a destination and guiding a user to the destination, comprising:

a preference parameter storing unit which stores preference parameters calculated as usage frequencies of preference items by using probe data collected from a plurality of vehicles, wherein each usage frequency is a ratio of a number of travel counts of the respective preference item for a road link to a number of total travel counts for the road link;

an attribute information storing unit which stores user attribute data; and

a route searching unit which selects at least one preference parameter similar to the attribute data, adjusts a cost of each link according to the selected preference parameter such that the cost decreases as a match between the selected preference parameter and a user'"'"'s preference increases, and determines a minimum-cost route from a departure place to a destination.

9. The navigation apparatus according to claim 8, further comprising a travel data storing unit which stores travel data on an own vehicle,

wherein the user attribute data represents a route preference calculated from the travel data.

10. The navigation apparatus according to claim 8, further comprising a preference parameter updating unit which updates, by communication or via a portable recording medium, the preference parameters stored in the preference parameter storing unit.