Optimum route determination apparatus

Claim 2

In an optimum route determination apparatus which, according to a destination set by a vehicle operator, reads road map data of an area containing a departure point and that destination out of a road map memory and which determines an optimum route leading from the departure point to the destination based on the road map data, said optimum route determination apparatus comprising: a plurality of specific points selected from said road map data on the basis of a fixed criterion; an optimum route from each departure point in which one of said specific points is a destination and which has been calculated in advance; a route memory (3B) having a route table in which data of an end route between said one of said specific points and at least the next specific point through which said optimum route passes are stored in correspondence with said each departure point and said one of said specific points; initialization means (6) for setting a departure point, a specific point near to a destination of a trip, and specific points along said optimum route; and initial route acquisition means (7) for retrieving said route table to acquire said data of said end route in accordance with said departure point and said specific point set by said initialization means (6).

Claim 3

An optimum route determination apparatus as set forth in claim 1, wherein said road map data comprise combination of nodes and links, and points (P1, p11, p12, etc.) on said road map are specified by said links.

Claim 4

An optimum route determination apparatus as set forth in claim 2, wherein said road map data comprise combination of nodes and links, and points (P1, p11, p12, etc.) on said road map are specified by said links.

Claim 5

An optimum route determination apparatus as set forth in claim 1, wherein said road map data comprise combination of nodes and links, and points (P1, p11, p12, etc.) on said road map are specified by said nodes.

Claim 6

An optimum route determination apparatus as set forth in claim 2, wherein said road map data comprise combination of nodes and links, and points (P1, p11, p12, etc.) on said road map are specified by said nodes.

Claim 7

An optimum route determination apparatus as set forth in claim 1, wherein said route table of said route memory (3B) has stored therein data of said initial route as a distance between said departure point (P1) and said destination (p42) is longer than a predetermined distance.

Claim 8

An optimum route determination apparatus as set forth in claim 2, wherein said route table of said route memory (3B) has stored therein data of said end route as a distance between said departure point (P1) and said destination (p42) is longer than a predetermined distance.

Claim 9

In an optimum route determination apparatus which, according to a destination set by a vehicle operator, reads road map data of an area containing a departure point and that destination out of a road map memory for a road map and which determines an optimum route leading from the departure point to the destination based on the road map data, said optimum route determination apparatus comprising: a plurality of specific points selected from said road map on the basis of a fixed criterion; an optimum route (L1) leading to each destination in which one of said specific points is a departure point and which has been calculated in advance; a route memory (3B) having a route table in which data of an initial route leading from said one of said specific points to at least the next specific point through which said optimum route passes are stored in correspondence with said each destination and said one of said specific points; initialization means (6) for setting a destination (Q1), a specific point (P0) near to a vehicle's current location, and specific points (P1, P2, P3) along said optimum route; and initial route acquisition means (7) for retrieving said route table to acquire said data of said initial route in accordance with said destination (Q1) and said specific point (P0, P1, P2, P3) set by said initialization means (6); and when the same initial route is stored with respect to different destinations (Q1, Q2, Q3), said route table of said route memory (3B) having stored therein said the same initial route in correspondence with an aggregation (m2) of said different destinations.

Claim 10

In an optimum route determination apparatus which, according to a destination set by a vehicle operator, reads road map data of an area containing a departure point and that destination out of a road map memory and which determines an optimum route leading from the departure point to the destination based on the road map data, said optimum route determination apparatus comprising: a plurality of specific points selected from said road map data on the basis of a fixed criterion; an optimum route (L1) from each departure point in which one of said specific points is a destination and which has been calculated in advance; a route memory (3B) having a route table in which data of an end route between said one of said specific points and at least the next specific point through which said optimum route passes are stored in correspondence with said each departure point and said one of said specific points; initialization means (6) for setting a departure point (P0), a specific point near to a destination of a trip, and specific points along said optimum route; and initial route acquisition means (7) for retrieving said route table to acquire said data of said end route in accordance with said departure point and said specific point set by said initialization means (6); and when the same end route is stored with respect to different destinations (Q1, Q2, Q3), said route table of said route memory (3B) having stored therein said the same end route in correspondence with an aggregation (m2) of said different destinations.

Claim 11

An optimum route determination apparatus as set forth in claim 9, wherein said road map data comprise combination of nodes and links, and points (P0, p11, p12, P1, etc.) on said road map are specified by said links.

Claim 12

An optimum route determination apparatus as set forth in claim 10, wherein said road map data comprise combination of nodes and links, and points (P0, p11, p12, P1, etc.) on said road map are specified by said links.

Claim 13

An optimum route determination apparatus as set forth in claim 9, wherein said road map data comprise combination of nodes and links, and points (P0, p11, p12, P1, etc.) on said road map are specified by said nodes.

Claim 14

An optimum route determination apparatus as set forth in claim 10, wherein said road map data comprise combination of nodes and links, and points (P0, p11, p12, P1, etc.) on said road map are specified by said nodes.

Claim 15

An optimum route determination apparatus as set forth in claim 9, wherein said route table of said route memory (3B) has stored therein data of said initial route as a distance between said departure point (P0) and said destination (Q1) is longer than a predetermined distance.

Claim 16

An optimum route determination apparatus as set forth in claim 10, wherein said route table of said route memory (3B) has stored therein data of said end route as a distance between said departure point (P0) and said destination (Q1) is longer than a predetermined distance.