On-Vehicle Information Terminal Route Characteristics Extraction Apparatus And Route Characteristics Display Method

• US 20070198172A1
• Filed: 09/15/2004
• Published: 08/23/2007
• Est. Priority Date: 09/18/2003
• Status: Active Grant

• Current Assignee: Clarion Co., Ltd. (Faurecia SA)
• Original Assignee: Xanavi Informatics Corporation (Hitachi, Ltd.)
• Inventors: Minagawa, Hiroshi, Oikubo, Wataru, Sumizawa, Akio
• Granted Patent: US 7,546,205 B2
• Time in Patent Office: Days
• US Class Current: 701/201
• CPC Class Codes: G01C 21/34 Route searching; Route guidance
• CPC Class Codes: G08G 1/0969 having a display in the form of a map

Abstract

An on-vehicle information terminal comprises a route search unit that searches for a plurality of routes connecting a current position to a destination and a characteristics extraction unit that extracts characteristics of each route searched by the route search unit based upon geographic names. The on-vehicle information terminal displays the characteristics of individual routes extracted by the characteristics extraction unit at a display device.

Claims

1. An on-vehicle information terminal, comprising:

a route search unit that searches for a plurality of routes connecting a current position to a destination; and

a characteristics extraction unit that extracts characteristics of each route searched by the route search unit based upon geographical names, wherein;

the characteristics of individual routes extracted by the characteristics extraction unit are displayed at a display device.

2. An on-vehicle information terminal according to claim 1, wherein:

the characteristics extraction unit extracts characteristics of each route based upon road names of roads included in the route.

3. An on-vehicle information terminal according to claim 2, wherein:

the characteristics extraction unit extracts for each route a road name of a road extending over a longest distance among the roads included in the route as part of the characteristics of the route.

4. An on-vehicle information terminal according to claim 3, wherein:

the characteristics extraction unit prepares for each route a block name-distance table constituted with the road names of the roads included in the route and distances over which individual blocks of the route each having the road name extend based upon route data containing link information of the route;

the characteristics extraction unit identifies the road name of a longest distance block extending over a longest distance in the route based upon the block name-distance table thus prepared; and

the characteristics extraction unit extracts the identified road name.

5. An on-vehicle information terminal according to claim 4, wherein:

the characteristics extraction unit sets a longest distance block among all the routes as a target block;

the characteristics extraction unit sets a route containing the target block as a target route;

the characteristics extraction unit sets routes other than the target route as a comparison route group;

the characteristics extraction unit compares a first distance value obtained by multiplying the distance of the target block by a predetermined multiplicand with a distance (a second distance value) of a block (in the comparison block group) included in the comparison route group and bearing a name identical to the name of the target block;

the characteristics extraction unit extracts the road name of the target block for the target route if the first distance value is greater than the second distance value; and

the characteristics extraction unit extracts the road name of the target block for the target route and a route (an identified route) containing a block in the comparison block group corresponding to the second distance value equal to or greater than the first distance value if the first distance value is not greater than the second distance value.

6. An on-vehicle information terminal according to claim 5, wherein:

if the first distance value is greater than the second distance value, the characteristics extraction unit sets a longest distance block in the comparison block group as a new target block and sets as a new target route a route containing the new target block; and

if the first distance value is not greater than the second distance value, the characteristics extraction unit sets as a new target block a longest distance block among the blocks included in the target route excluding the target block.

7. An on-vehicle information terminal according to claim 1, wherein:

the characteristics extraction unit extracts characteristics of each route based upon geographical names of geographical areas through which the route passes.

8. An on-vehicle information terminal according to claim 7, wherein:

the characteristics extraction unit sets geographical points on the individual routes to be compared with one another and extracts geographical names associated with the geographical points geographically most distanced from one another as part of characteristics of the individual routes.

9. An on-vehicle information terminal according to claim 8, wherein:

the characteristics extraction unit sets points corresponding to individual positions breaking up each of the routes into a predetermined number of equal segments as route breakup points;

the characteristics extraction unit calculates sums each representing a total of linear distances between route breakup points at corresponding positions in the routes among the route breakup points having been set;

the characteristics extraction unit sets route breakup points with a largest sum as maximum distance route breakup points; and

the characteristics extraction unit extracts geographical names of geographical points at which the maximum distance route breakup points are present.

10. An on-vehicle information terminal according to claim 9, wherein:

the characteristics extraction unit sets names of highest-order units of administrative districts in the geographical names corresponding to the geographical points at which the maximum distance route breakup points are present as target geographical names of the individual routes; and

the characteristics extraction unit extracts the target geographical names having been set for the individual routes.

11. An on-vehicle information terminal according to claim 10, wherein:

the characteristics extraction unit makes a decision as to whether or not one of the target geographical names having been set for the individual routes is different from the others;

if it is decided that there is a route with a target geographical name different from the others, the characteristics extraction unit sets as new maximum distance route breakup points a set of route breakup points with a greatest sum of linear distances between the route breakup points at corresponding positions set for the routes excluding the route with the different target geographical name and sets names of highest-order units of administrative districts in the geographical names corresponding to geographical points at which the new maximum distance route breakup points thus set are present as new target geographical names for the routes having the newly set maximum distance route breakup points; and

if there is no route with a target geographical name different from the others, the characteristics extraction unit sets names of next highest-order units of administrative districts after administrative districts corresponding to the current target geographical names as new target geographical names for the individual routes.

12. An on-vehicle information terminal according to claim 11, wherein:

if there is no route with a target geographical name different from the others and the target geographical names all indicate a lowest-order unit of administrative district, the characteristics extraction unit sets a new maximum distance route breakup points a set of route breakup points with a largest sum of linear distances between the route breakup points at corresponding positions in the individual routes among other route breakup points excluding the current maximum distance route breakup points.

13. An on-vehicle information terminal according to claim 1, wherein:

if identical characteristics are extracted in correspondence to a plurality of routes, the characteristics extraction unit sequentially assigns numbers to be used to identify the individual routes.

14. A route characteristics extraction apparatus, comprising:

a route search unit that searches for a plurality of routes connecting a current point to a destination;

a characteristics extraction unit that extracts characteristics of each route searched by the route search unit based upon geographical names; and

an output unit that provides an external recipient with a signal output indicating the characteristics of the individual routes extracted by the characteristics extraction unit.

15. A route characteristics display method comprising:

searching for a plurality of routes connecting a current point to a destination;

extracting characteristics of each searched route based upon geographical names; and

displaying the extracted characteristics of each route.