Navigation system and program for controlling the same

• US 20070005240A1
• Filed: 06/29/2006
• Published: 01/04/2007
• Est. Priority Date: 07/01/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation, Denso IT Laboratory, Inc. (DENSO Corporation)
• Original Assignee: DENSO Corporation, Denso IT Laboratory, Inc. (DENSO Corporation)
• Inventors: Suzuki, Takamitsu, Mizuno, Nobuhiro, Hara, Kosuke, Iwasaki, Hirotoshi, Oumi, Masanori
• Granted Patent: US 7,437,240 B2
• Time in Patent Office: Days
• US Class Current: 701/209
• CPC Class Codes: G01C 21/3484 Personalized, e.g. from learned user behaviour or user-defined profiles
• 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 1/096888 where input information is obtained using learning systems, e.g. history databases

Abstract

A navigation system, having a route calculation unit for providing a navigation route from a start point to a destination based on an evaluation of a plurality of cost parameters by an evaluation function, includes a storage unit for storing a weighting factor determination relation for determining a weighting factor of the cost parameter based on a travel situation of predetermined type identified in a specific length of time and a weighting factor determination unit for determining the weighting factor based on the weighting factor determination relation and the travel situation derived from an actual state of traveling.

Claims

1. A navigation system having a route calculation unit for providing a navigation route from a start point to a destination based on an evaluation of a plurality of cost parameters by an evaluation function, the navigation system comprising:

a storage unit for storing a weighting factor determination relation for determining a weighting factor of the cost parameter based on a travel situation of predetermined type identified in a specific length of time; and

a weighting factor determination unit for determining the weighting factor based on the weighting factor determination relation and the travel situation derived from an actual state of traveling.

2. The navigation system as in claim 1,

wherein the weighting factor determination relation determines the weighting factor based on user information having an unchanging quality in addition to the travel situation, and

the weighting factor determination unit uses the weighting factor determination relation, the user information and the travel situation to determine the weighting factors of the plurality of the cost parameters after the travel situation is adapted to the actual state of traveling.

3. The navigation system as in claim 1,

wherein the weighting factor determination relation includes an observation parameter having binary condition for representing a weekday and a holiday.

4. The navigation system as in claim 1,

wherein the weighting factor determination relation is defined by Bayesian network model.

5. The navigation system as in claim 1,

wherein a plurality of the weighting factors in the cost evaluation function are organized as a weighting factor table,

a plurality of the weighting factor tables are organized as a weighting factor table set, and

the weighting factor determination unit determines the weighting factors by selecting the weighting factor table in the weighting factor table set.

6. The navigation system as in claim 5 further comprising:

a preference determination unit for determining user preference regarding a route attribute based on the travel situation of the actual state of traveling and the user information, wherein a route attribute reference determiner is employed for determining the user preference based on the travel situation and the user information;

a route option calculation unit in the route calculation unit for calculating plural optional routes respectively by employing the weighting factor table determined by the weighting factor determination unit;

a route attribute determination unit in the route calculation unit for determining the user preference for each of the optional routes calculated by the route option calculation unit, wherein the route attribute in the user preference for each of the optional routes is determined by the preference determination unit; and

a route determination unit in the route calculation unit for determining a preferred route by evaluating the route attribute of each of the optional routes determined by the route attribute determination unit in terms of matching degree to the user preference determined by the preference determination unit.

7. The navigation system as in claim 5 further comprising:

a similar route determination unit for determining the optional route that is most similar to a navigation route actually traveled from among the plural optional routes based on the evaluation by the evaluation function that uses weighting factor table chosen from the weighting factor table set; and

a relation determination unit in the weighting factor determination unit for modifying the weighting factor determination relation, wherein the weighting factor determination relation determined by the relation determination unit is modified so that the similar route determination unit determines the most similar optional route to the actually traveled navigation route based on the weighting factor table suitable for the travel situation in the actually traveled navigation route.

8. A program for controlling the navigation system as in claim 1, the program stored in a storage medium for use in a computer that is functional as the navigation system comprising a procedure of:

executing a function of the weighting factor determination unit.