U.S. patent application number 09/739966 was filed with the patent office on 2001-06-21 for route selecting method, route selecting system, and recording medium.
Invention is credited to Yagyu, Takeshi.
Application Number | 20010004725 09/739966 |
Document ID | / |
Family ID | 18477515 |
Filed Date | 2001-06-21 |
United States Patent
Application |
20010004725 |
Kind Code |
A1 |
Yagyu, Takeshi |
June 21, 2001 |
Route selecting method, route selecting system, and recording
medium
Abstract
There are provided a route selecting method, a route selecting
system, and a recording medium capable of selecting a route in
which a road on which a user has traveled is suitably reflected. A
section traveling route generation portion 6 receives a traveling
track of a vehicle detected by a current position and traveling
track detection portion 2 and an optimum route searched for by an
optimum route searching portion 5, and compare the traveling track
and the optimum route, to extract different road sections as
section traveling routes. A section traveling route storage portion
7 stores the extracted section traveling route and its attribute
information. A crossing section examination portion 8 first
examines, in the case of guiding, whether or not the section
traveling route taking as a section a part, between two arbitrary
points, of the optimum route searched for by the optimum route
searching portion 5 exists in the section traveling route storage
portion 7, and extracts the section traveling route from the
section traveling route storage portion 7 when the section
traveling route exists. A guiding route generation portion 9
replaces the part, between the two points, of the optimum route
with the section traveling route on the basis of the optimum route
and the extracted section traveling route, to generate a guiding
route.
Inventors: |
Yagyu, Takeshi; (Yokohama,
JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
18477515 |
Appl. No.: |
09/739966 |
Filed: |
December 20, 2000 |
Current U.S.
Class: |
701/425 ;
340/995.1 |
Current CPC
Class: |
G01C 21/3484
20130101 |
Class at
Publication: |
701/210 ;
340/995 |
International
Class: |
G01C 021/30 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 1999 |
JP |
362694/1999 |
Claims
What is claimed is:
1. A route selecting method for selecting an optimum route on a map
in the travel of a vehicle, comprising the steps of: searching for
an optimum route between two points using map data required to
select a route; collecting traveling tracks on which the vehicle
travels; comparing said optimum route searched for and said
traveling tracks collected, to store only different route parts on
the traveling tracks as section traveling routes; when a user is
guided, comparing said optimum route searched for and all of said
section traveling routes stored, to examine whether the section
traveling route crossing the optimum route (hereinafter referred to
as a crossing section traveling route) exists; replacing, with
respect to said crossing section traveling route examined, a
section on said optimum route which crosses the crossing section
traveling route with a corresponding part of the crossing section
traveling route, to generate a guiding route; and guiding the user
using said guiding route generated.
2. The route selecting method according to claim 1, wherein said
guiding step comprises the step of displaying, when said guiding
route is displayed, said optimum route, together with the guiding
route, in such a manner that they can be distinguished.
3. The route selecting method according to claim 1, wherein said
storing step comprises the step of deleting, with respect to said
section traveling route already stored (hereinafter referred to as
existing section traveling route), the existing section traveling
route when the vehicle newly travels on a different route in the
same section (from the same start point to the same end point) as
the existing section traveling route.
4. The route selecting method according to claim 2, wherein said
storing step comprises the step of deleting, with respect to said
section traveling route already stored (hereinafter referred to as
existing section traveling route), the existing section traveling
route when the vehicle newly travels on a different route in the
same section (from the same start point to the same end point) as
the existing section traveling route.
5. The route selecting method according to claim 1, wherein said
storing step comprises the step of accumulatively storing the
number of times the vehicle travels on said section traveling
route, together with the section traveling route, and said
generating step comprises the step of using, for the replacement,
only said crossing section traveling route on which the vehicle
travels not less than a particular number of times.
6. The route selecting method according to claim 5, wherein said
storing step comprises the step of reducing, with respect to said
section traveling route already stored (hereinafter referred to as
existing section traveling route), the number of times the vehicle
travels on the existing section traveling route when the vehicle
newly travels on a different route in the same section (from the
same start point to the same end point) as the existing section
traveling route.
7. The route selecting method according to claim 1, further
comprising the step of examining whether the section traveling
route including a current position of the vehicle and having a
point crossing said guiding route in the travel direction is stored
on the basis of said traveling tracks collected and said guiding
route generated, and generating, when the section traveling route
exists, a new guiding route from the current position to a
destination point using the section traveling route and said
guiding route, said guiding step comprising the step of guiding the
user using said new guiding route generated when it is determined
that the current position of the vehicle deviates from said guiding
route.
8. The route selecting method according to claim 1, wherein said
storing step comprises the step of storing circumstances where the
vehicle travels on said section traveling route, together with the
section traveling route, and said generating step comprises the
step of using, for the replacement, only said crossing section
traveling route whose circumstances stored at said storing step
conform to the current circumstances.
9. The route selecting method according to claim 1, further
comprising the step of inputting a route (a traveling track) on
which a user desires to travel on a map, said storing step
comprising the step of finding said section traveling route using
the traveling track inputted at said inputting step in place of the
traveling tracks collected at said collecting step.
10. The route selecting method according to claim 1, wherein said
storing step comprises the step of individually storing said
section traveling route for each user, and said examining step and
said generating step each comprise the step of performing
processing using only said section traveling route corresponding to
the user.
11. The route selecting method according to claim 1, wherein said
storing step comprises the step of determining said section
traveling route to be stored in accordance with judgment given from
the user.
12. A route selecting system for selecting an optimum route on a
map in the travel of a vehicle, comprising: a map data storage
portion for storing map data required to select a route; a current
position and traveling track detection portion for finding a
current position and a traveling track of the vehicle; an
information input portion for inputting particular information (a
destination point and a departure point of a route, a current time
zone and day of the week, an expected time zone and day of the week
of departure/arrival, and the like.) in accordance with an
instruction issued by a user; an optimum route searching portion
for searching for an optimum route between two points using said
map data and said particular information; a section traveling route
generation portion for comparing the optimum route searched for by
said optimum route searching portion and the traveling track found
in said current position and travelling track detection portion, to
extract only different route parts on the traveling track as
section traveling routes; a section traveling route storage portion
for storing said section traveling routes; a crossing section
examination portion for, when the user is guided, comparing the
optimum route searched for by said optimum route searching portion
and all of said section traveling routes stored in said section
traveling route storage portion, to examine whether the section
traveling route crossing the optimum route (hereinafter referred to
as a crossing section traveling route) exists; a guiding route
generation portion for replacing, with respect to said crossing
section traveling route examined by said crossing section
examination portion, a section on said optimum route which crosses
the crossing section traveling route with a corresponding part of
the crossing section traveling route, to generate a guiding route;
and a map display output portion for guiding the user using said
guiding route generated by said guiding route generation
portion.
13. The route selecting system according to claim 12, wherein said
map display output portion displays, when said guiding route is
displayed, said optimum route, together with the guiding route, in
such a manner that they can be distinguished.
14. The route selecting system according to claim 12, wherein said
section traveling route generation portion deletes, with respect to
said section traveling route already stored in said section
traveling route storage portion (hereinafter referred to as
existing section traveling route), the existing section traveling
route when the vehicle newly travels on a different route in the
same section (from the same start point to the same end point) as
the existing section traveling route.
15. The route selecting system according to claim 13, wherein said
section traveling route generation portion deletes, with respect to
said section traveling route already stored in said section
traveling route storage portion (hereinafter referred to as
existing section traveling route), the existing section traveling
route when the vehicle newly travels on a different route in the
same section (from the same start point to the same end point) as
the existing section traveling route.
16. The route selecting system according to claim 12, wherein said
section traveling route storage portion accumulatively stores the
number of times the vehicle travels on said section traveling
route, together with the section traveling route, and said guiding
route generation portion uses, for the replacement, only said
crossing section traveling route on which the vehicle travels not
less than a predetermined number of times.
17. The route selecting system according to claim 16, wherein said
section traveling route generation portion reduces, with respect to
said section traveling route already stored in said section
traveling route storage portion (hereinafter referred to as
existing section traveling route), the number of times the vehicle
travels on the existing section traveling route when the vehicle
newly travels on a different route in the same section (from the
same start point to the same end point) as the existing section
traveling route.
18. The route selecting system according to claim 12, further
comprising a return route selection portion receiving said current
position found by said current position and traveling track
detection portion and said guiding route generated by said guiding
route generation portion, to examine whether the section traveling
route including the current position and having a point crossing
said guiding route in the travel direction exists in said section
traveling route storage portion, and generate, when the section
traveling route exists, a new guiding route from the current
position to a destination point using the section traveling route
and said guiding route, said map display output portion guiding the
user using said new guiding route generated by said return route
selection portion when it is determined that the current position
of the vehicle deviates from said guiding route.
19. The route selecting system according to claim 12, wherein said
section traveling route storage portion stores circumstances where
the vehicle travels on said section traveling route, together with
the section traveling route, and said guiding route generation
portion uses, for the replacement, only said crossing section
traveling route whose circumstances stored in said section
traveling route storage portion conform to the current
circumstances.
20. The route selecting system according to claim 12, further
comprising a travelling track input portion for inputting a route
(a traveling track) on which a user desires to travel on a map,
said section traveling route generation portion using the traveling
track inputted to said traveling track input portion in place of
the traveling tracks found by said current position and traveling
track detection portion, to extract said section traveling
route.
21. The route selecting system according to claim 12, wherein said
section traveling route storage portion individually stores said
section traveling route for each user, and said crossing section
examination portion and said guiding route generation portion each
perform processing using only said section traveling route
corresponding to the user.
22. The route selecting system according to claim 12, wherein said
section traveling route storage portion determines said section
traveling route to be stored in accordance with judgment given from
the user.
23. A recording medium having a program executed in a computer
recorded thereon, the program at least comprising the steps of:
searching for an optimum route between two points using map data
required to select a route; collecting traveling tracks on which a
vehicle travels; comparing said optimum route searched for and said
traveling tracks collected, to store only different route parts on
the traveling tracks as section traveling routes; when a user is
guided, comparing said optimum route searched for and all of said
section traveling routes stored, to examine whether the section
traveling route crossing the optimum route (hereinafter referred to
as a crossing section traveling route) exists; replacing, with
respect to said crossing section traveling route examined, a
section on said optimum route which crosses the crossing section
traveling route with a corresponding part of the crossing section
traveling route, to generate a guiding route; and guiding the user
using said guiding route generated.
24. The recording medium according to claim 23, wherein said
guiding step comprises the step of displaying, when said guiding
route is displayed, said optimum route, together with the guiding
route, in such a manner that they can be distinguished.
25. The recording medium according to claim 23, wherein said
storing step comprises the step of deleting, with respect to said
section traveling route already stored (hereinafter referred to as
existing section traveling route), the existing section traveling
route when the vehicle newly travels on a different route in the
same section (from the same start point to the same end point) as
the existing section traveling route.
26. The recording medium according to claim 24, wherein said
storing step comprises the step of deleting, with respect to said
section traveling route already stored (hereinafter referred to as
existing section traveling route), the existing section traveling
route when the vehicle newly travels on a different route in the
same section (from the same start point to the same end point) as
the existing section traveling route.
27. The recording medium according to claim 23, wherein said
storing step comprises the step of accumulatively storing the
number of times the vehicle travels on said section traveling
route, together with the section traveling route, and said
generating step comprises the step of using, for the replacement,
only said crossing section traveling route on which the vehicle
travels not less than a predetermined number of times.
28. The recording medium according to claim 27, wherein said
storing step comprises the step of reducing, with respect to said
section traveling route already stored (hereinafter referred to as
existing section traveling route), the number of times the vehicle
travels on the existing section traveling route when the vehicle
newly travels on a different route in the same section (from the
same start point to the same end point) as the existing section
traveling route.
29. The recording medium according to claim 23, further comprising
the step of examining whether the section traveling route including
the current position of the vehicle and having a point crossing
said guiding route in the travel direction is stored on the basis
of said traveling tracks collected and said guiding route
generated, and generating, when the section traveling route exists,
a new guiding route from the current position to a destination
point using the section traveling route and said guiding route,
said guiding step comprising the step of guiding the user using
said new guiding route generated when it is determined that the
current position of the vehicle deviates from said guiding
route.
30. The recording medium according to claim 23, wherein said
storing step comprises the step of storing circumstances where the
vehicle travels on said section traveling route, together with the
section traveling route, and said generating step comprises the
step of using, for the replacement, only said crossing section
traveling route whose circumstances stored in said storing step
conform to the current circumstances.
31. The recording medium according to claim 23, further comprising
the step of inputting a route (a traveling track) on which a user
desires to travel on a map, said storing step comprising the step
of finding said section traveling route using the traveling track
inputted at said inputting step in place of the traveling tracks
collected at said collecting step.
32. The recording medium according to claim 23, wherein said
storing step comprises the step of individually storing said
section traveling route for each user, and said examining step and
said generating step each comprise the step of performing
processing using only said section traveling route corresponding to
the user.
33. The recording medium according to claim 23, wherein said
storing step comprises the step of determining said section
traveling route to be stored in accordance with judgment given from
the user.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a route selecting
method, a route selecting system, and a recording medium, and more
particularly, to a method used for a car navigation system for
automatically selecting an optimum route between a departure point
and a destination point which are designated on a map, a system
using the method, and a medium having a program for carrying out
the method recorded thereon.
[0003] 2. Description of the Background Art
[0004] In recent years, navigation systems for guiding vehicles
have rapidly started to spread as electronic techniques have been
developed. The navigation systems include one comprising a route
selecting system for automatically selecting an optimum route from
a departure point to a destination point (for example, a shortest
distance arrival route or a minimum time arrival route) in order to
improve the convenience of a user. The conventional route selecting
system will be simply described.
[0005] In the conventional route selecting system, an example of a
method of finding an optimum route for guiding a vehicle is a
method disclosed in Japanese Patent Laid-Open Publication No.
59-105113 (1984-105113) entitled "Method of Automatically Guiding
Vehicle" (hereinafter referred to as a first conventional method).
The first conventional method is for finding an optimum route
between a departure point and a destination point from data
representing a network of roads by using a Dijkstra method, or the
like, which is one of optimum route determining methods. The theory
of the Dijkstra method is described in "Data Structure and
Algorithm" (BAIFUKAN CO., LTD, issued in 1990, pp. 179 to pp. 183)
written by A. V. Eiho et al. and translated by Ono, for
example.
[0006] In contrast with the above-mentioned first conventional
method, an example of a method of finding an optimum route to which
a travel experience of a user is added is a method disclosed in
Japanese Patent Laid-Open Publication No. 8-201088 (1996-201088)
entitled "On-vehicle Navigation Device having Route Searching
Function" (hereinafter referred to as a second conventional
method). In the second conventional method, an evaluation value of
a road on which a user travels is changed depending on the
frequency of travel and is stored. A road having a small evaluation
value is selected in preference when a route is searched for the
next time.
[0007] Another example of a method of finding an optimum route to
which another taste of a user is added is a method disclosed in
Japanese Patent Laid-Open Publication No. 11-64030 (1999-64030)
entitled "Navigation Device" (hereinafter referred to as a third
conventional method). In the third conventional method, a
correction made by a user is reflected on an optimum route found by
searching based on a departure point to a destination point for
storage, and the route reflecting the correction is presented as a
shortest route when the route from the same departure point to the
same destination point is searched for again.
[0008] In a case where the evaluation value of the road on which
the user travels is changed, as in the conventional second method,
however, when a route different from the route at the time of
changing the evaluation value (a route which differs in a departure
point and/or a destination point) is searched for, a route forcedly
using a road having an experience of travel (having a small
evaluation value) may, in some cases, be selected.
[0009] In a case where the route reflecting the user's correction
is stored, as in the third conventional method, even for route
searching that may utilize such user-corrected route, if a
departure point and/or a destination point differs from that of the
user-corrected route, a route which does not reflect the
user-correction may be selected.
SUMMARY OF THE INVENTION
[0010] Therefore, an object of the present invention is to provide
a route selecting method capable of selecting a route in which a
road on which a user has traveled is suitably reflected, a system
using the method, and a recording medium having a program for
executing the method recorded thereon.
[0011] The present invention has the following features to solve
the problem above.
[0012] A first aspect of the present invention is directed to a
route selecting method for selecting an optimum route on a map in
the travel of a vehicle, comprising the steps of:
[0013] searching for an optimum route between two points using map
data required to select a route;
[0014] collecting traveling tracks on which the vehicle
travels;
[0015] comparing the optimum route searched for and the traveling
tracks collected, to store only different route parts on the
traveling tracks as section traveling routes;
[0016] when a user is guided, comparing the optimum route searched
for and all the section traveling routes stored, to examine whether
the section traveling route crossing the optimum route (hereinafter
referred to as a crossing section traveling route) exists;
[0017] replacing, with respect to the crossing section traveling
route examined, a section on the optimum route which crosses the
crossing section traveling route with a corresponding part of the
crossing section traveling route, to generate a guiding route;
and
[0018] guiding the user using the guiding route generated.
[0019] As described above, in the first aspect, the section
traveling route in only the section in which the vehicle travels
upon deviating from the optimum route is stored, and the user is
guided, when the optimum route capable of using the section is
searched for next time, on a route obtained by replacing the route
in the section with the stored section traveling route.
Consequently, a route in which a road on which the user once
traveled is suitably reflected is found depending on current
circumstances, thereby making it possible to guide the user.
[0020] Preferably, the guiding step comprises the step of
displaying, when the guiding route is displayed, the optimum route,
together with the guiding route, in such a manner that they can be
distinguished.
[0021] Both the guiding route including the route on which the user
once traveled and the optimum route in calculation are thus
displayed, thereby making it possible for the user to refer to not
only the guiding route but also the optimum route.
[0022] Preferably, the storing step comprises the step of deleting,
with respect to the section traveling route already stored
(hereinafter referred to as existing section traveling route), the
existing section traveling route when the vehicle newly travels on
a different route in the same section (from the same start point to
the same end point) as and different from the existing section
traveling route.
[0023] Accordingly. when the vehicle travels on a new route
different from the existing section traveling route (the section
traveling route on which the vehicle once traveled), data
representing the existing section traveling route is deleted,
thereby making it possible for the route on which the vehicle once
traveled but has not recently traveled not to be reflected in the
guiding route.
[0024] Preferably, the storing step comprises the step of
accumulatively storing the number of times the vehicle travels on
the section traveling route, together with the section traveling
route, and
[0025] the generating step comprises the step of using, for the
replacement, only the crossing section traveling route on which the
vehicle travels not less than a particular number of times.
[0026] The number of times the vehicle travels on the section
traveling route is thus together recorded, and the section
traveling route is reflected in the guiding route only when the
vehicle travels not less than a particular number of times, thereby
making it possible to prevent the route or the like at which the
vehicle accidentally dropped in from being reflected in the guiding
route.
[0027] Preferably, the storing step comprises the step of reducing,
with respect to the existing section traveling route, the number of
times the vehicle travels on the existing section traveling route
when the vehicle newly travels on a different route in the same
section as the existing section traveling route.
[0028] Accordingly, when the vehicle thus travels on a new route
different from the existing section traveling route, the number of
times the vehicle travels on the existing section traveling route
is reduced, thereby making it possible to reflect the section
traveling route which is high in the frequency of utilization in
the guiding route in preference.
[0029] Preferably, the route selecting method further comprises the
step of
[0030] examining whether the section traveling route including a
current position of the vehicle and having a point crossing the
guiding route in the travel direction is stored on the basis of the
traveling tracks collected and the guiding route generated, and
generating, when the section traveling route exists, a new guiding
route from the current position to a destination point using the
section traveling route and the guiding route,
[0031] the guiding step comprising the step of guiding the user
using the new guiding route generated when it is determined that
the current position of the vehicle deviates from the guiding
route.
[0032] Accordingly, when the current position thus deviates from
the guiding route, the route to the destination point is newly
generated on the basis of the route on which the vehicle once
traveled, thereby making it possible to guide a return route using
the route on which the user has experience to travel. Accordingly,
it is possible to enhance a user's feeling of relief.
[0033] Preferably, the storing step comprises the step of storing
circumstances where the vehicle travels on the section traveling
route, together with the section traveling route, and
[0034] the generating step comprises the step of using, for the
replacement, only the crossing section traveling route whose
circumstances stored at the storing step conform to the current
circumstances.
[0035] The circumstances where the vehicle travels on the section
traveling route is thus together stored, and only the section
traveling route conforming to the current circumstances is
reflected in the guiding route, thereby making it possible to
select the optimum route depending on the circumstances.
[0036] Preferably, the route selecting method comprises the step of
inputting a route (a traveling track) on which a user desires to
travel on a map,
[0037] the storing step comprising the step of finding the section
traveling route using the traveling track inputted at the inputting
step in place of the traveling tracks collected at the collecting
step.
[0038] Accordingly, the route (the traveling track) desired by the
user is inputted, and the section traveling route in the section
different from the optimum route is stored using the route, thereby
making it possible to reflect the route conforming to the desire of
the user in the guiding route even if the user does not actually
travel.
[0039] Preferably, the storing step comprises the step of
individually storing the section traveling route for each user,
and
[0040] the examining step and the generating step each comprise the
step of performing processing using only the section traveling
route corresponding to the user.
[0041] Consequently, it is possible to guide an optimum route
corresponding to an actual driver.
[0042] Preferably, the storing step comprises the step of
determining the section traveling route to be stored in accordance
with judgment given from the user
[0043] Consequently, it is possible to guide a more optimum route
in which the intention of a driver is reflected.
[0044] A second aspect of the present invention is directed to a
route selecting system for selecting an optimum route on a map in
the travel of a vehicle, comprising:
[0045] a map data storage portion for storing map data required to
select a route;
[0046] a current position and traveling track detection portion for
finding a current position and a traveling track of the
vehicle;
[0047] an information input portion for inputting particular
information (a destination point and a departure point of a route,
a current time zone and day of the week, an expected time zone and
day of the week of departure/arrival, and the like) in accordance
with an instruction issued by a user;
[0048] an optimum route searching portion for searching for an
optimum route between two points using the map data and the
particular information;
[0049] a section traveling route generation portion for comparing
the optimum route searched for by the optimum route searching
portion and the traveling track found in the current position and
travelling track detection portion, to extract only different route
parts on the traveling track as section traveling routes;
[0050] a section traveling route storage portion for storing the
section traveling routes;
[0051] a crossing section examination portion for, when the user is
guided, comparing the optimum route searched for by the optimum
route searching portion and all of the section traveling routes
stored in the section traveling route storage portion, to examine
whether the crossing section traveling route exists;
[0052] a guiding route generation portion for replacing, with
respect to the crossing section traveling route examined by the
crossing section examination portion, a section on the optimum
route which crosses the crossing section traveling route with a
corresponding part of the crossing section traveling route, to
generate a guiding route; and
[0053] a map display output portion for guiding the user using the
guiding route generated by the guiding route generation
portion.
[0054] As described above, in the second aspect, the section
traveling route in only the section in which the vehicle travels
upon deviating from the optimum route is stored, and the user is
guided, when the optimum route capable of using the section is
searched for next time, on a route obtained by replacing the route
in the section with the stored section traveling route.
Consequently, a route in which a road on which the user once
traveled is suitably reflected is found depending on current
circumstances, thereby making it possible to guide the user.
[0055] Preferably, the map display output portion displays, when
the guiding route is displayed, the optimum route, together with
the guiding route, in such a manner that they can be
distinguished.
[0056] Accordingly, both the guiding route including the route on
which the user once traveled and the optimum route in calculation
are displayed, thereby making it possible for the user to refer to
not only the guiding route but also the optimum route.
[0057] Preferably, the section traveling route generation portion
deletes, with respect to the existing section traveling route, the
existing section traveling route when the vehicle newly travels on
a different route in the same section as the existing section
traveling route.
[0058] Accordingly, when the vehicle thus travels on a new route
different from the existing section traveling route (the section
traveling route on which the vehicle once traveled), data
representing the existing section traveling route is deleted,
thereby making it possible for the route on which the vehicle once
traveled but has not recently traveled not to be reflected in the
guiding route.
[0059] Preferably, the section traveling route storage portion
accumulatively stores, the number of times the vehicle travels on
the section traveling route, together with the section traveling
route, and
[0060] the guiding route generation portion uses, for the
replacement, only the crossing section traveling route on which the
vehicle travels not less than a predetermined number of times.
[0061] The number of times the vehicle travels on the section
traveling route is thus together recorded, and the section
traveling route is reflected in the guiding route only when the
vehicle travels not less than a particular number of times, thereby
making it possible to prevent the route or the like at which the
vehicle accidentally dropped in from being reflected in the guiding
route.
[0062] Preferably, the section traveling route generation portion
reduces, with respect to the existing section traveling route, the
number of times the vehicle travels on the existing section
traveling route when the vehicle newly travels on a different route
in the same section as the existing section traveling route.
[0063] When the vehicle thus travels on a new route different from
the existing section traveling route, the number of times the
vehicle travels on the existing section traveling route is reduced,
thereby making it possible to reflect the section traveling route
which is high in the frequency of utilization in the guiding route
in preference.
[0064] Preferably, the route selecting system further comprises a
return route selection portion receiving the current position found
by the current position and traveling track detection portion and
the guiding route generated by the guiding route generation
portion, to examine whether the section traveling route including
the current position and having a point crossing the guiding route
in the travel direction exists in the section traveling route
storage portion, and generate, when the section traveling route
exists, a new guiding route from the current position to a
destination point using the section traveling route and the guiding
route,
[0065] the map display output portion guiding the user using the
new guiding route generated by the return route selection portion
when it is determined that the current position of the vehicle
deviates from the guiding route.
[0066] When the current position thus deviates from the guiding
route, the route to the destination point is newly generated on the
basis of the route on which the vehicle once traveled, thereby
making it possible to guide a return route using the route on which
the user has an experience to travel. Accordingly, it is possible
to enhance a user's feeling of relief.
[0067] Preferably, the section traveling route storage portion
stores circumstances where the vehicle travels on the section
traveling route, together with the section traveling route, and
[0068] the guiding route generation portion uses, for the
replacement, only the crossing section traveling route whose
circumstances stored in the section traveling route storage portion
conform to the current circumstances.
[0069] The circumstances where the vehicle travels on the section
traveling route are thus together stored, and only the section
traveling route conforming to the current circumstances is
reflected in the guiding route, thereby making it possible to
select the optimum route depending on the circumstances.
[0070] Preferably, the route selecting system further comprises a
travelling track input portion for inputting a route (a traveling
track) on which a user desires to travel on a map,
[0071] the section traveling route generation portion using the
traveling track inputted to the traveling track input portion in
place of the traveling tracks found by the current position and
traveling track detection portion, to extract the section traveling
route.
[0072] Accordingly, the route (the traveling track) desired by the
user is inputted, and the section traveling route in the section
different from the optimum route is stored using the route, thereby
making it possible to reflect the route conforming to the desire of
the user in the guiding route even if the vehicle does not actually
travel.
[0073] Preferably, the section traveling route storage portion
individually stores the section traveling route for each user,
and
[0074] the crossing section examination portion and the guiding
route generation portion each perform processing using only the
section traveling route corresponding to the user.
[0075] Consequently, it is possible to guide an optimum route
corresponding to an actual driver.
[0076] More preferably, the section traveling route storage portion
determines the stored section traveling route in accordance with
judgment given from the user.
[0077] Consequently, it is possible to guide a more optimum route
in which the intention of the driver is reflected.
[0078] Typically, in a computer comprising a storage device (a ROM,
a RAM, a hard disk, etc.) storing predetermined program data which
can be executed at each of the steps and a CPU (Central Processing
Unit) for executing the program data, the route selecting method
described in the first aspect is realized. In this case,
predetermined program data capable of executing each of the steps
described in the first aspect may be introduced into the computer
through a writable recording medium (a CD-ROM, a floppy disk,
etc.)
[0079] These and other objects, features, aspects and advantages of
the present invention will become more apparent from the following
detailed description of the present invention when taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0080] FIG. 1 is a block diagram showing the configuration of a
route selecting system according to an embodiment of the present
invention;
[0081] FIGS. 2a to 2e are diagrams showing an example of operations
performed by a section traveling route generation portion 6 shown
in FIG. 1;
[0082] FIGS. 3a and 3b are diagrams showing an example of section
traveling route data stored in a section traveling route storage
portion 7 shown in FIG. 1;
[0083] FIGS. 4a to 4c are diagrams for explaining an example of
operations performed by a crossing section examination portion 8
and a guiding route generation portion 9 shown in FIG. 1;
[0084] FIGS. 5a to 5e are diagrams for explaining an example of a
pattern for generating a guiding route on the basis of section
traveling route data in the guiding route generation portion 9
shown in FIG. 1;
[0085] FIGS. 6a and 6b are diagrams for explaining an example of
conditions at the time of using section traveling route data in the
guiding route generation portion 9 shown in FIG. 1;
[0086] FIGS. 7a to 7d are diagrams showing an example of operations
performed by a simple return route selection portion 12 shown in
FIG. 1;
[0087] FIG. 8 is a flow chart showing an example of route selecting
operations performed by a route selecting system according to an
embodiment of the present invention;
[0088] FIG. 9 is a flow chart showing an example of detailed
operation at a sub-routine step S104 shown in FIG. 8;
[0089] FIG. 10 is a flow chart showing an example of detailed
operation at a sub-routine step S105 shown in FIG. 8;
[0090] FIG. 11 is a flow chart showing an example of detailed
operation at a sub-routine step S106 shown in FIG. 8; and
[0091] FIG. 12 is a flow chart showing an example of detailed
operation at a sub-routine step S107 shown in FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0092] FIG. 1 is a block diagram showing the configuration of a
route selecting system according to an embodiment of the present
invention. In FIG. 1, the route selecting system according to the
present embodiment comprises a map data storage portion 1, a
current position and traveling track detection portion 2, a
traveling track input portion 3, an information input portion 4, an
optimum route searching portion 5, a section traveling route
generation portion 6, a section traveling route storage portion 7,
a crossing section examination portion 8, a guiding route
generation portion 9, a map display portion 10, an output portion
11, and a simple return route selection portion 12.
[0093] Operations performed by the respective portions in the route
selecting system according to the embodiment of the present
invention will be described.
[0094] The map data storage portion 1 stores data for map display
used for displaying a map presented to a user and road network data
used for detecting the current position of a vehicle and selecting
an optimum route from a departure point to a destination point.
Typically, the map data storage portion 1 has each of the data in
the form of a recording medium such as a CD-ROM, and reads out the
necessary data from the recording medium by an incorporated driving
mechanism (not shown).
[0095] The current position and traveling track detection portion 2
first finds an approximate current position and an approximate
traveling track of the vehicle using the speed of the vehicle or an
angle at which the vehicle turns and a radio wave from a satellite
(a radio wave from GPS (Global Positioning System)). The current
position and traveling track detection portion 2 then refers to the
road network data stored in the map data storage portion 1, to
accurately find the current position and the traveling track of the
vehicle.
[0096] The traveling track input portion 3 is operated in response
to an input operation of the user, generates a traveling track in
accordance with an instruction issued by the user, and outputs the
generated traveling track to the section traveling route generation
portion 6. The traveling track input portion 3 is a constituent
required when the user does not cause the vehicle to actually
travel to generate a traveling track (i.e., a virtual traveling
track).
[0097] The information input portion 4 is operated in response to
an input operation of the user, and outputs to the optimum route
searching portion 5 information relating to a destination point for
route searching (a departure point, a current time zone and day of
the week, an expected time zone and day of the week of
departure/arrival, etc., if required) in accordance with an
instruction issued by the user.
[0098] The optimum route searching portion 5 uses the road network
data stored in the map data storage portion 1, to search for and
select an optimum route from a departure point to a destination
point. The departure point is set using information relating to the
current position of the vehicle which is detected by the current
position and traveling track detection portion 2 or the departure
point reecived from the information input portion 4. Further,
information relating to the destination point received from the
information input portion 4 is used for setting the destination
point. Further, the optimum route searching portion 5 receievs
information (attribute information) relating to the current time
zone and day of the week or the time zone and day of the week in
and on which the user intends to depart (or arrive) from the
information input portion 4, as required.
[0099] The section traveling route generation portion 6 receives
the traveling track of the vehicle from the current position and
traveling track detection portion 2 or the traveling track input
portion 3, and receives the selected optimum route from the optimum
route searching portion 5. The section traveling route generation
portion 6 compares the optimum route and the traveling track, to
extract, as a section traveling route, a road section different
from the optimum route on the traveling track (a road section
having two points, i.e., a start point and an end point on the
optimum route). The section traveling route thus extracted is
outputted to the section traveling route storage portion 7 from the
section traveling route generation portion 6. The section traveling
route generation portion 6 specifies every section traveling route
having its two points on the traveling track out of the section
traveling routes already stored in the section traveling route
storage portion 7, and increases the number of times of traveling
for the section traveling route which is the same as the traveling
track, while decreasing the number of times of traveling for the
section traveling route which is different from the traveling
track. The section traveling route generation portion 6 outputs the
number of times of traveling (attribute information) which is
increased or decreased to the section traveling route storage
portion 7.
[0100] The section traveling route storage portion 7 stores as
section traveling route data the section traveling route and the
number of times of traveling which are received from the section
traveling route generation portion 6. At this time, the section
traveling route storage portion 7 together stores the attribute
information such as the time zone and day of the week in and on
which the vehicle travels.
[0101] The crossing section examination portion 8 receives the
optimum route from the optimum route searching portion 5. The
crossing section examination portion 8 examines whether or not the
section traveling route having as a section a part, between
arbitrary two points (conforming to the travel direction), of the
optimum route exists in the section traveling route storage portion
7. When such section traveling route exists, the crossing section
examination portion 8 acquires the section traveling route from the
section traveling route storage portion 7, and outputs the section
traveling route, together with the optimum route, to the guiding
route generation portion 9. The section traveling route having as a
section a part, between arbitrary two points, of the optimum route
may be not only a road having a start point and an end point on the
optimum route but also a road crossing the optimum route on its
way.
[0102] The guiding route generation portion 9 replaces the part
between the two points of the optimum route with the section
traveling route on the basis of the optimum route and the section
traveling route (the whole or a part) which are received from the
crossing section examination portion 8, to generate a guiding
route. The guiding route generation portion 9 outputs the generated
guiding route to the map display portion 10.
[0103] The map display portion 10 refers to the map display data
stored in the map data storage portion 1, to generate image data
for displaying a map including the current position of the vehicle
found by the current position and traveling track detection portion
2 and its vicinity or a map in a range desired by the user. The map
display portion 10 together generates, when the guiding route
generated by the guiding route generation portion 9 (or a new
guiding route generated by the simple return route selection
portion 12, described later) is included in the range of the map to
be displayed, image data representing the guiding route. Further,
the map display portion 10 outputs guidance information for guiding
the vehicle (for example, voice information and/or display
information "Please turn right at an intersection 100 m ahead.") on
the basis of the current position of the vehicle and the guiding
route. The guidance information is not a primary object of the
present invention and hence, the description thereof is
omitted.
[0104] The output portion 11 comprises a display, a speaker, and so
forth, and outputs image data, guidance information, and so forth
fed from the map display portion 10 by screen display and
voice.
[0105] The simple return route selection portion 12 receives, when
the vehicle deviates from the guiding route during guidance, the
current position of the vehicle and the guiding route from the map
display portion 10, and examines whether or not the section
traveling route having, as a section, a section between two points,
i.e., the current position of the vehicle and an arbitrary point on
the guiding route, exists in the section traveling route storage
portion 7. When such section traveling route exists, the simple
return route selection portion 12 acquires the section traveling
route from the section traveling route storage portion 7, and
generates a new guiding route obtained by replacing a part, between
the two points, of the guiding route with the acquired section
traveling route. The simple return route selection portion 12
outputs the generated new guiding route to the map display portion
10 as a guiding route. When such section traveling route does not
exist, a route returning to the optimum route based on the prior
art is searched for in the simple return route selection portion 12
(or the optimum route searching portion 5).
[0106] Referring now to FIGS. 2a to 2e, operations performed by the
section traveling route generation portion 6 shown in FIG. 1 will
be described in detail by taking specific examples.
[0107] FIGS. 2a to 2e are diagrams showing examples of generation
of a section traveling route and conversion of attribute
information which are performed by the section traveling route
generation portion 6. FIG. 2a illustrates a traveling track of a
vehicle provided by the current position and traveling track
detection portion 2 (or the traveling track input portion 3) and an
optimum route searched for by the optimum route searching portion
5. The section traveling route generation portion 6 compares the
traveling track (indicated by a broken line) with the optimum route
(indicated by a solid line) shown in FIG. 2a, to specify a
different road section, and extracts a traveling track from a start
point to an end point (indicated simply as "S" and "E",
respectively in the drawings) of the different road section as
shown in FIG. 2b as a section traveling route A. Simultaneously,
the section traveling route generation portion 6 specifies a time
zone (seven o'clock to nine o'clock in this example) and a day of
the week (Friday in this example) in and on which the vehicle
travels. Further, the section traveling route generation portion 6
sets the number of times of traveling which is attribute
information relating to the section traveling route A to "one"
(indicated simply as "travel-times: 1" in the drawings). When the
section traveling route A has already been stored in the section
traveling route storage portion 7, the section traveling route
generation portion 6 increases the number of times of traveling
currently stored by one. The section traveling route generation
portion 6 outputs the section traveling route A thus found,
together with the attribute information, to the section traveling
route storage portion 7.
[0108] On the other hand, when the vehicle travels on the optimum
route (the optimum route=the traveling track) in a case where the
section traveling route A has already existed in the section
traveling route storage portion 7, as shown in FIG. 2c, the section
traveling route generation portion 6 decreases the number of times
of traveling which is the attribute information relating to the
section traveling route A by one. The section traveling route on
which the number of times of traveling is "zero" may be deleted
from the section traveling route storage portion 7.
[0109] When the traveling is started from a point different form a
departure point of the optimum route, as shown in FIG. 2d, the
section traveling route generation portion 6 extracts, as a section
traveling route B, a road section from the point at which the
traveling is started to a point merged into the optimum route. When
the traveling is terminated in a point different from a destination
point of the optimum route, as shown in FIG. 2e, the section
traveling route generation portion 6 extracts, as a section
traveling route C, a road section from a point deviating from the
optimum route to the point at which the traveling is
terminated.
[0110] Referring now to FIGS. 3a and 3b, contents stored in the
section traveling route storage portion 7 shown in FIG. 1 will be
described in detail by taking specific examples.
[0111] FIGS. 3a and 3b are diagrams showing examples of section
traveling route data stored in the section traveling route storage
portion 7. FIG. 3a is a diagram showing road network data and a
certain section traveling route. The road network data is composed
of intersections and roads (links) connecting the intersections.
The links are respectively assigned inherent numbers. The section
traveling route is indicated by a string of link numbers. The
section traveling route shown in FIG. 3a is stored as a route
passing through links L53, L22, L62, and L33 in this order. FIG. 3b
illustrates an example of contents stored as the section traveling
route data in the section traveling route storage portion 7, and
the number of times of traveling, a day of the week on which the
vehicle travels, and a time zone in which the vehicle travels are
together stored in correspondence with the section traveling route
represented by the string of link numbers.
[0112] Although the section traveling route in the section
traveling route storage portion 7 is represented by the string of
link numbers, it may be stored by a storing method in another data
format, provided that a route is seen in the format, for example, a
string of data representing intersections through which the vehicle
passes (a string of node numbers). Although a distinction in a time
zone, a day of the week, or the like is stored as attribute
information corresponding to the section traveling route, another
distinction in which traffic conditions are assumed to be changed,
for example, a distinction in weekdays/holidays, in
morning/afternoon/night/midnight, or in the day when money is
collected/other days may be stored.
[0113] Referring now to FIGS. 4a to 4c, operations performed by the
crossing section examination portion 8 and the guiding route
generation portion 9 shown in FIG. 1 will be described in detail by
taking specific examples.
[0114] FIGS. 4a to 4c are diagrams for explaining examples of the
procedural flow of examining a section traveling route crossing an
optimum route searched for in the optimum route searching portion
5, and then generating a guiding route on the basis of the results
of the examination. FIG. 4a is an image view positionally showing
section traveling routes D and E represented by section traveling
route data stored in the section traveling route storage portion 7
on a map plane. FIG. 4b is an image view showing an optimum route
from a departure point to a destination point which is found by the
optimum route searching portion 5 so as to overlap with FIG.
4a.
[0115] In such a positional relationship (FIG. 4b), the crossing
section examination portion 8 first examines whether or not the
section traveling route D crosses the optimum route. In this
example, the section traveling route D and the optimum route do not
cross each other. Accordingly, the crossing section examination
portion 8 does not take the section traveling route D as a
processing object. The crossing section examination portion 8 then
examines whether or not the section traveling route E crosses the
optimum route. In this example, a start point and an end point of
the section traveling route E cross the optimum route. Accordingly,
the crossing section examination portion 8 takes the section
traveling route E as a processing object and extracts a route
between the two points which cross the optimum route (a traveling
route in a crossing section) from the section traveling route E. In
this example, both the start point and the end point of the section
traveling route E are positioned on the optimum route. Accordingly,
the section traveling route E is extracted as it is as the
traveling route in the crossing section. The traveling route in the
crossing section thus extracted and the optimum route are outputted
to the guiding route generation portion 9.
[0116] The guiding route generation portion 9 deletes a crossing
section part of the optimum route, generates a route into which the
extracted traveling route in the crossing section is inserted in
place of the crossing section part, and outputs the generated route
to the map display portion 10 as a guiding route.
[0117] Referring now to FIGS. 5a to 5e, examples of a pattern of an
optimum route and a section traveling route in a case where section
traveling route data is reflected in a guiding route in the guiding
route generation portion 9 shown in FIG. 1. FIGS. 5a to 5e are
diagrams for explaining patterns for generating a guiding route on
the basis of the section traveling route data.
[0118] First consider a case where both a start point and an end
point of a section traveling route F cross an optimum route (FIG.
5a). In this case, a route from the start point to the end point of
the section traveling route F is extracted as a traveling route in
a crossing section. A corresponding section part of the optimum
route is replaced with the extracted traveling route in the
crossing section, thereby generating a guiding route.
[0119] Then consider a case where there exist two points crossing
the optimum route halfway on the section traveling route F (FIG.
5b). In this case, only a route between the two points crossing the
optimum route on the section traveling route F is extracted as a
traveling route in a crossing section. A corresponding section part
of the optimum route is replaced with the extracted traveling route
in the crossing section, thereby generating a guiding route.
[0120] Furthermore consider a case where a section traveling route
and an optimum route cross each other at only one point. This case
can be classified into the following three cases.
[0121] First consider a case where the optimum route is started
from a point spaced apart from a departure point, and a section
traveling route G is closer to the departure point than the point
at which the optimum route is started (FIG. 5c). In this case, a
route between one point on the section traveling route G closest to
the departure point (which is assumed to be a crossing point) and
the other point at which the section traveling route G crosses the
optimum route is extracted as a traveling route in a crossing
section. A part behind the other point of the optimum route is
replaced with the extracted traveling route in the crossing
section, thereby generating a guiding route.
[0122] Then consider a case where the optimum route is terminated
in a point spaced apart from a destination point, and a section
traveling route H is closer to the destination point than the point
at which the optimum route is terminated (FIG. 5d). In this case, a
route between one point at which the section traveling route H
crosses the optimum route and the other point on the section
traveling route H closest to the destination point (which is
assumed to be a crossing point) is extracted as a traveling route
in a crossing section. Apart ahead of the one point of the optimum
route is replaced with the extracted traveling route in the
crossing section, thereby generating a guiding route.
[0123] Then consider a case where a section traveling route I and
the optimum route cross each other at only one point in a position
spaced apart from a departure point and a destination point (FIG.
5e). In this case, the section traveling route I does not cross the
optimum route at two points. Accordingly, the section traveling
route I is not a processing object in the generation of the guiding
route.
[0124] It goes without saying that a section traveling route having
no point crossing the optimum route is not a processing object in
generating the guiding route.
[0125] Referring now to FIGS. 6a and 6b, an example of conditions
under which section traveling route data is reflected in a guiding
route in the guiding route generation portion 9 shown in FIG. 1
will be described.
[0126] FIG. 6a is a diagram for explaining a case where a section
traveling route J is reflected in a guiding route on the basis of
conditions by the number of times of traveling. Such conditioning
is for making it possible to consider only a section traveling
route which is utilized at a high frequency bur not a section
traveling route on which the vehicle accidentally traveled (for
example, a case where the vehicle is bypassed by road repairing) in
generating the guiding route. As an example, conditions are set
such that only a section traveling route on which the vehicle
travels not less than two times is replaced with an optimum route
in the guiding route generation portion 9.
[0127] Under such set conditions, in the case of a route on which a
vehicle first traveles, a section traveling route relating to the
route is not stored in the section traveling route storage portion
7. In this case, an optimum route found by the optimum route
searching portion 5 is presented to a user as a guiding route. When
the vehicle travels on a road different from the guiding route (the
optimum route), a new section traveling route J is generated from
its traveling track, and the number of times of traveling is stored
as "one" in the section traveling route storage portion 7.
[0128] When the route between the same points is then searched for
again, the optimum route is the same route as that searched for
last time. However, there exists a section traveling route J
crossing the optimum route stored last time. Therefore, the
crossing section examination portion 8 extracts the section
traveling route J and outputs, together with the optimum route, the
section traveling route J to the guiding route generation portion
9. In this case, the number of times of traveling on the section
traveling route J is still "one". Accordingly, a limitation on the
above-mentioned conditions is applied. Therefore, as a guiding
route for the current (second) traveling, the same route as the
guiding route when the vehicle traveled for the last time (first
time) is outputted. When the vehicle traveled for the second time
on a road having the same traveling track as the traveling track on
which the vehicle traveled for the first time, the number of times
of traveling on the section traveling route J, which has already
been stored, is increased by one to "two".
[0129] Thereafter, when the route between the same points is
further searched for again, the same optimum route as that for the
first traveling and the second traveling is found. Since the number
of times of traveling on the section traveling route J to be
outputted to the guiding route generation portion 9 is "two",
however, a route which has been replaced with the section traveling
route J is set as a guiding route. Accordingly, for the third
traveling, the user can be guided by the same route as the route
(the traveling track) on which the vehicle actually traveled for
the first time and for the second time.
[0130] FIG. 6b is a diagram for explaining a case where a section
traveling route K is reflected in a guiding route on the basis of
conditions by a time zone and a day of the week. Such conditioning
is for making it possible to consider traffic conditions which vary
depending on a time factor (for example, a case where a road is
congested with commuter vehicles on weekdays, while not being
congested on holidays) in generating the guiding route. As an
example, the time zone that is attribute information is classified
in units of three hours (1 to 3 o'clock, 4 to 6 o'clock, 7 to 9
o'clock, 10 to 12 o'clock, 13 to 15 o'clock, 16 to 18 o'clock, 19
to 21 o'clock, and 22 to 24 o'clock), and the day of the week that
is attribute information is classified into weekdays from Monday to
Friday and holidays such as Saturday, Sunday, and public holidays.
The time zone and the day of the week are stored in the section
traveling route storage portion 7.
[0131] On the basis of the above-mentioned example, the section
traveling route K generated when the vehicle travels at 8 o'clock
on Friday is classified as "7 to 9 o'clock, weekday". When an
optimum route which should use the section traveling route K is
found in this state, for example, the day of the week and the time
on and at which the searching is performed is 8 o'clock on Monday,
the guiding route in which the section traveling route K is
reflected is generated. When the searching is performed at 20
o'clock on Monday and at 8 o'clock on Saturday, however, 20 o'clock
on Monday and 8 o'clock on Saturday do not coincide with the
conditions in the attribute information (the time zone and the day
of the week) relating to the section traveling route K.
Accordingly, a guiding route in which the section traveling route K
is not reflected is generated.
[0132] Although the classification based on the time zone and the
day of the week was described as an example, the classification may
be based on the taste of the user. For example, such conditions
that the section traveling route is reflected in only days each
having "8" assigned to its end (8-th, 18-th, and 28-th) may be set,
or an input device which can be freely set by the user may be
provided to determine the classification.
[0133] Referring now to FIGS. 7a to 7d, operations performed by the
simple return route selection portion 12 shown in FIG. 1 will be
described in detail by taking specific examples.
[0134] FIG. 7a illustrates a state where a vehicle travels in
accordance with a guiding route generated by the guiding route
generation portion 9 when a route from a departure point to a
destination point is found. FIG. 7b illustrates a state where the
vehicle deviates from the guiding route by the intention of a user.
At this time, the map display portion 10 senses that the vehicle
deviates from the guiding route, and outputs the guiding route
before the deviation and the current position of the vehicle to the
simple return route selection portion 12. In response, the simple
return route selection portion 12 searches for, in the section
traveling route storage portion 7, a section traveling route on
which the current position exists and which has crossing points
with the guiding route based on the current position of the vehicle
and the guiding route which are fed from the map display portion
10. When a corresponding section traveling route L exists, the
simple return route selection portion 12 acquires the section
traveling route L from the section traveling route storage portion
7 (FIG. 7c). The simple return route selection portion 12 extracts,
as a traveling route in a crossing section, a part from the current
position to a point crossing the guiding route of the acquired
section traveling route L, and connects the traveling route in the
crossing section to the guiding route, to newly generate a guiding
route from the current position to the destination point (FIG. 7d)
and output the guiding route to the map display portion 10.
[0135] Referring now to FIGS. 8 to 12, description is made of route
selecting operations performed by the route selecting system
according to the embodiment of the present invention.
[0136] FIG. 8 is a flow chart showing an example of the route
selecting operations performed by the route selecting system
according to the embodiment of the present invention. FIGS. 9 to 12
are flow charts showing examples of more detailed operations at
sub-routine steps S104 to S107 shown in FIG. 8. As an example,
operations in a case where a vehicle travels from its current
position to a destination point inputted by a user. In order to
make the description more definite, the date and the day of the
week, etc. are not specified, and only the number of times of
traveling is specified with respect to attribute information
relating to section traveling route data.
[0137] First referring to FIG. 8, the optimum route searching
portion 5 receives the position coordinates (longitude and
latitude) of the destination point from the information input
portion 4 in response to an input operation performed by the user
(step S101). The optimum route searching portion 5 also receives
the date and time of departure, as required. The optimum route
searching portion 5 then receives the coordinates (longitude and
latitude) of the current position of the vehicle and the travel
direction of the vehicle from the current position and traveling
track detection portion 2, to set a departure point (step S102).
The optimum route searching portion 5 uses road network data stored
in the map data storage portion 1 (further traffic information,
etc. in some cases), to search for and select an optimum route from
the departure point to the destination point (step S103). The route
searching processing at step S103 is performed using a minimum
route searching method such as a Dijkstra method conventionally
known.
[0138] The crossing section examination portion 8 and the guiding
route generation portion 9 then perform guiding route generation
processing in order to find a guiding route for guiding the user
from the current position to the destination point (step S104). The
detailed operation at step S104 is shown in FIG. 9.
[0139] Referring to FIG. 9, operations in the guiding route
generation processing (FIG. 8, step S104) will be described.
[0140] When the guiding route generation processing is started, the
crossing section examination portion 8 first initializes a region
which stores a section traveling route crossing an optimum route
(hereinafter referred to as a crossing section traveling route)
found by examination (step S201). The crossing section examination
portion 8 then determines whether or not all section traveling
routes represented by section traveling route data stored in the
section traveling route storage portion 7 are examined (step S202).
At the current time point, i.e., immediately after the
initialization at step S201, the examination has not been made yet.
Accordingly, the procedure proceeds to step S203. The crossing
section examination portion 8 selects, as an examination object,
one of the section traveling routes which have not been examined
yet from the section traveling route data (step S203).
[0141] The crossing section examination portion 8 then uses the
section traveling route selected at step S203 and the optimum route
found at step S103, and traces the optimum route from a departure
point to a destination point, to examine whether or not there is a
point crossing the selected section traveling route (step S204).
When there is no crossing point as a result of the examination at
step S204, the procedure is returned to step S202. At step S202,
the crossing section examination portion 8 examines another section
traveling route which has not been examined yet. On the other hand,
when there is a crossing point as a result of the examination at
step S204, the crossing section examination portion 8 stores the
crossing point as a crossing-point M (step S205).
[0142] After the crossing-point M is found at step S205, the
crossing section examination portion 8 traces the optimum route
from the crossing-point M to the destination point, to examine
whether or not there is a point recrossing the section traveling
route (step S206). When there is a recrossing point as a result of
the examination at step S206, the crossing section examination
portion 8 stores the recrossing point as a crossing-point N (step
S207). On the other hand, when there is no recrossing point as a
result of the examination at step S206, the crossing section
examination portion 8 further searches for a point closest to the
current destination point (hereinafter referred to as a destination
closest vicinity point) in the direction of a track on which the
vehicle travels from the crossing-point M on the selected section
traveling route, and then examines whether or not the destination
closest vicinity point is closer to the destination point than a
final point on the optimum route (an end point of the route) (step
S208).
[0143] When the destination closest vicinity point is closer to the
destination point at step S208, the crossing section examination
portion 8 stores the destination closest vicinity point as the
crossing-point N (step S207). On the other hand, when the
destination closest vicinity point is farther from the destination
point at step S208, the crossing section examination portion 8
further searches for a point closest to the departure point
(hereinafter referred to as a departure closest vicinity point) in
the opposite direction to the direction of the track on which the
vehicle travels from the crossing-point M on the selected section
traveling route, and then examines whether or not the departure
closest vicinity point is closer to the departure point than a
first point on the optimum route (a start point of the route) (step
S209). When the departure closest vicinity point is closer to the
first point at step S209, the crossing section examination portion
8 stores the crossing-point M previously stored as a crossing-point
N again, and stores the departure closest vicinity point as a new
crossing-point M (step S210). On the other hand, when the departure
closest vicinity point is farther than the first point at step
S209, the crossing section examination portion 8 determines that
the selected section traveling route is not the crossing section
traveling route. Therefore, the procedure is returned to step S202.
At step S202, the other section traveling route which has not been
examined yet is examined.
[0144] The crossing section examination portion 8 then extracts
from the section traveling route storage portion 7 a route from the
found crossing-point M to the crossing-point N, and stores the
route as the crossing section traveling route after performing the
processing at step S207 or S210 (step S211). Even if the other
crossing section traveling route has already been stored, the
contents thereof are not deleted (overwritten), and the section
traveling route newly extracted is additionally stored. When the
crossing section traveling route has been stored, the procedure is
returned to the foregoing step S202. At step S202, the crossing
section examination portion 8 examines the other section traveling
route which has not been examined yet.
[0145] When steps S202 to S211 are repeated, to terminate, in the
crossing section examination portion 8, the examination of all the
section traveling routes represented by the section traveling route
data stored in the section traveling route storage portion 7, the
guiding route generation portion 9 then acquires the optimum route
found at step S103 and the stored crossing section traveling route
(step S212). At this time, the optimum route found at step S103 is
left as it is in the crossing section examination portion 8. The
guiding route generation portion 9 then replaces a part of the
optimum route that corresponds to a section between the
crossing-point N and the crossing-point N with that of the crossing
section traveling route (step S213).
[0146] A guiding route in which the crossing section traveling
route is reflected in the optimum route is thus generated by the
guiding route generation portion 9, thereby terminating the guiding
route generation processing at step S104. The procedure is returned
to the main routine shown in FIG. 8.
[0147] Referring to FIG. 8 again, after the guiding route
generation processing (step S104) is terminated, the map display
portion 10, the output portion 11, and the simple return route
selection portion 12 perform traveling state processing in order to
provide guiding information to the user using a guiding route (step
S105). Detailed operations at step S105 are shown in FIG. 10.
[0148] Referring to FIG. 10, the operations in the traveling state
processing (FIG. 8, step S105) will be described.
[0149] When the traveling state processing is started, the map
display portion 10 sets the guiding route found at step S104 as a
user-guidance route provided to the user (step S301). The map
display portion 10 receives the current position of the vehicle
from the current position and traveling track detection portion 2
(step S302). The map display portion 10 then compares the received
current position and the user-guidance route, to examine whether or
not the vehicle has reached the destination point (step S303).
[0150] If the vehicle has reached the destination point as a result
of the examination at step S303, the map display portion 10
terminates the traveling state processing at step S105. The
procedure is returned to the main routine shown in FIG. 8. On the
other hand, if the vehicle has not reached the destination point as
a result of the examination at step S303, the map display portion
10 further determines whether or not the current position of the
vehicle is on the user-guidance route (step S304).
[0151] If determined at step S304 that the current position of the
vehicle is on the user-guidance route, the map display portion 10
generates guiding information "Turn right at an intersection 300 m
ahead", for example, conforming to the user-guidance route on the
basis of the current position of the vehicle, to present the
guiding information to the user using the output portion 11 (step
S305). When the guiding information relating to the current
position has been presented, the procedure is returned to step S302
again. At step S302, the map display portion 10 examines the
subsequent current position to which the vehicle is moved.
[0152] Steps S302 to S305 are repeated until the vehicle travels on
the user-guidance route to reach the destination point.
[0153] When the map display portion 10 determines at step S304 that
the current position of the vehicle deviates from the user-guidance
route, however, the simple return route selection portion 12
examines whether or not the section traveling route having, as a
section, a part between the current position and a point on the
user-guidance route exists in the section traveling route storage
portion 7 (step S306). When the section traveling route exists as a
result of the examination at step S306, the simple return route
selection portion 12 extracts the section traveling route from the
section traveling route storage portion 7 as a return route from
the current position to the user-guidance route (step S307). On the
other hand, when the section traveling route does not exist as a
result of the examination at step S306, the simple return route
selection portion 12 finds the return route from the current
position to the user-guidance route by reading out data from the
map data storage portion 1 and searching for the optimum route
again (step S309).
[0154] The simple return route selection portion 12 generates a new
user-guidance route leading from the current point to the
destination point by connecting the return route found at step S307
or S309 to the user-guidance route (step S308). When the new
user-guidance route has been generated, the procedure is returned
to the foregoing step S302. At step S302, the subsequent position
to which the vehicle is moved is examined by the map display
portion 10.
[0155] Referring to FIG. 8 again, after the traveling state
processing (step S105) is terminated, the section traveling route
generation portion 6 performs section traveling route addition
processing (step S106). Detailed operations at step S106 are shown
in FIG. 11.
[0156] Referring to FIG. 11, the operations in the section
traveling route addition processing (FIG. 8, step S106) will be
described.
[0157] When the section traveling route addition processing is
started, the section traveling route generation portion 6 receives
a traveling track on which the vehicle travels until it reaches the
destination point from the departure point from the current
position and traveling track detection portion 2 or the traveling
track input portion 3, and receives the optimum route found at step
S103 by the optimum route searching portion 5 (step S401). The
section traveling route generation portion 6 compares the received
traveling track with the optimum route, to first determine whether
or not their departure points differ from each other (step S402).
When it is determined at step S402 that they do not differ, the
procedure directly proceeds to step S407. At step S407, the section
traveling route generation portion 6 performs processing. On the
other hand, when it is determined at step S402 that they differ,
the section traveling route generation portion 6 extracts a
traveling track in a section on which the vehicle travels from the
departure point to the optimum route (step S403). The section
traveling route generation portion 6 examines whether or not the
extracted traveling track has already been stored as a section
traveling route in the section traveling route storage portion 7
(step S404). The section traveling route generation portion 6
increases the number of times of traveling on the section traveling
route by one if the extracted traveling track has already been
stored at step S404 (step S405), while storing the traveling track
extracted at step S403 as a new section traveling route (the number
of times of traveling is one) in the section traveling route
storage portion 7 (step S406) if it has not been stored.
Thereafter, the procedure proceeds to step S407.
[0158] When it is determined at step S402 that the departure points
do not differ, or when the processing at step S405 or S406 is
terminated, the section traveling route generation portion 6
further examines a point at which the traveling track and the
optimum route then separate from each other leading to the
destination point (step S407).
[0159] If the traveling track and the optimum route are the same
until the vehicle reaches the destination point as a result of the
examination at step S407, the section traveling route generation
portion 6 terminates the section traveling route addition
processing at step S106. The procedure is returned to the main
routine shown in FIG. 8. On the other hand, if there is a point at
which the traveling track and the optimum route separate from each
other (a separating point) as a result of the examination at step
S407, the section traveling route generation portion 6 further
examines a point at which the traveling track and the optimum route
are merged (a merging point) ahead the separating point (step
S408). The section traveling route generation portion 6 extracts a
traveling track in a section from the separating point to the
merging point if the merging point is found as a result of the
examination at step S408 (step S409), while extracting a traveling
track in a section from the separating point to the destination
point if the merging point is not found (step S410).
[0160] The section traveling route generation portion 6 then
examines whether or not the traveling track extracted at step S409
or S410 has already been stored as a section traveling route in the
section traveling route storage portion 7 (step S411). The section
traveling route generation portion 6 increases the number of times
of traveling on the section traveling route by one (step S412) if
the traveling track has already been stored as a result of the
examination at step S411, while storing the extracted traveling
track as a new section traveling route (the number of times of
traveling is one) in the section traveling route storage portion 7
(step S413) if the traveling track has not been stored. Thereafter,
the procedure is returned to step S407.
[0161] Referring now to FIG. 8 again, after the section traveling
route addition processing (step S106) is terminated, the section
traveling route generation portion 6 performs section traveling
route deletion processing (step S107). Detailed operation at step
S107 are shown in FIG. 12.
[0162] Referring to FIG. 12, the operations in the section
traveling route deletion processing (FIG. 8, step S107) will be
described.
[0163] When the section traveling route deletion processing is
started, the section traveling route generation portion 6 receives
a traveling track on which the vehicle travels from the departure
point to the destination point from the current position and
traveling track detection portion 2 (or the traveling track input
portion 3, as required) (step S501). The section traveling route
generation portion 6 then determines whether or not all section
traveling routes represented by section traveling route data stored
in the section traveling route storage portion 7 are examined (step
S502). At the current time point, i.e., after step S501, the
examination has not been made yet. Therefore, the procedure
directly proceeds to step S503. The section traveling route
generation portion 6 selects, as an examination object, one of the
section traveling routes which have not been examined yet from the
section traveling route data (step S503).
[0164] The section traveling route generation portion 6 then
examines whether or not both a start point and an end point of the
selected section traveling route exist on the traveling track
received at step S501 (step S504). If the start point and the end
point do not exist on the traveling track as a result of the
examination at step S504, the section traveling route generation
portion 6 is done with examination on the selected section
traveling. Therefore, the procedure is returned to step S502. At
step S502, the section traveling route generation portion 6
examines the other section traveling route which has not been
examined yet. On the other hand, if the start point and the end
point exist on the traveling track as a result of the examination
at step S504, the section traveling route generation portion 6
further examines whether or not the traveling route in the section
between the start point and the end point differs from the
traveling track received at step S501 (step S505).
[0165] If the traveling route and the traveling track are the same
as a result of the examination at step S505, the section traveling
route generation portion 6 is done with examination on the selected
section traveling route. Therefore, the procedure is returned to
step S502. At step S502, the section traveling route generation
portion 6 examines the other section traveling route which has not
been examined yet. On the other hand, if they differ as a result of
the examination at step S505, the section traveling route
generation portion 6 examines whether or not the number of times of
traveling on the selected section traveling route is one (step
S506). If the number of times of traveling is one as a result of
the examination at step S506, data representing the selected
section traveling route is deleted from the section traveling route
storage portion 7. If the number of times of traveling is more than
one, the number of times of traveling is decreased by one and is
stored in the section traveling route storage portion 7. After the
selected section traveling route has thus been examined, the
procedure is returned to step S502. At step S502, the section
traveling route generation portion 6 examines the other section
traveling route which has not been examined yet.
[0166] When the foregoing steps S502 to S508 are repeated, to
terminate, in the section traveling route generation portion 6, the
examination of all the section traveling routes represented by the
section traveling route data stored in the section traveling route
storage portion 7, the section traveling route deletion processing
at step S107 is terminated. Thereafter, the procedure is returned
to the main routine shown in FIG. 8.
[0167] Referring now to FIG. 8 again, when the section traveling
route deletion processing (at step S107) is terminated, all the
route selection operations are terminated.
[0168] As described in the foregoing, according to the route
selecting system and the route selecting method according to the
embodiment, the section traveling route in only the section where
the vehicle travels upon deviating from the optimum route, together
with its attribute information, is stored. When the optimum route
capable of using the section next time is searched for, the user is
guided on a route obtained by replacing the section with the stored
section traveling route.
[0169] Consequently, a route in which a road on which the user once
traveled is reflected is found depending on the current
circumstances, thereby making it possible to guide the user.
[0170] Although in the above-mentioned embodiment, description was
made of a case where the Dijkstra method is used in the optimum
route searching portion 5, another route searching method may be
used. Although in the above-mentioned embodiment, the section
traveling route addition processing (step S106) and the section
traveling route deletion processing (step S107) in the section
traveling route generation portion 6 are performed after the
vehicle has reached the destination point based on the traveling
state processing (step S105), they may be performed simultaneously
with the traveling state processing (step S105) while the vehicle
is traveling toward the destination point.
[0171] When the route selecting system according to the present
embodiment is shared among a plurality of drivers, the section
traveling route data generated by the section traveling route
generation portion 6 may be classified for each of the drivers and
stored in the section traveling route storage portion 7. When any
driver is guided, the crossing section examination portion 8, the
guiding route generation portion 9, the map display portion 10, and
the simple return route selection portion 12 may use only the
section traveling route data corresponding to the driver to
generate a guiding route. Consequently, it is possible to guide the
optimum route corresponding to each driver. When such processing is
performed, information indicating who drives the vehicle may be
given to each of the above-mentioned constituent elements through
the information input portion 4.
[0172] Furthermore, in the above-mentioned embodiment, all the
section traveling routes extracted in the section traveling route
generation portion 6 are described as processing objects. However,
some of roads extracted as the section traveling routes may not be
liked by drivers. Examples are snowy roads and narrow mounting
roads. Therefore, it may be judged by the driver whether or not the
section traveling route extracted by the section traveling route
generation portion 6 is stored in the section traveling route
storage portion 7. Consequently, it is possible to guide a more
optimum route in which the intention of the driver is reflected.
Such judgment made by the driver may be inputted through the
information input portion 4.
[0173] While the invention has been described in detail, the
foregoing description is in all aspects illustrative and not
restrictive. It is understood that numerous other modifications and
variations can be devised without deviating from the scope of the
invention.
* * * * *