U.S. patent application number 09/195917 was filed with the patent office on 2001-10-04 for vehicle information acquisition system including capability to obtain information in blind spots.
Invention is credited to HASHIMOTO, TAKAHIRO.
Application Number | 20010027374 09/195917 |
Document ID | / |
Family ID | 18110900 |
Filed Date | 2001-10-04 |
United States Patent
Application |
20010027374 |
Kind Code |
A1 |
HASHIMOTO, TAKAHIRO |
October 4, 2001 |
VEHICLE INFORMATION ACQUISITION SYSTEM INCLUDING CAPABILITY TO
OBTAIN INFORMATION IN BLIND SPOTS
Abstract
A system for acquiring map information reliably even when a
vehicle is running in a blind area where the map information is not
acquirable in real time, assisting the vehicle to keep running
smoothly. In this system, necessary map information can be acquired
from an external information center upon request via a
communication device. Specifying data of a blind area in which the
map information is not acquirable in real time is previously stored
in a memory. Based on the specifying data stored in the memory and
a current position of the vehicle detected as by GPS, a processor
acquires the map information of the blind area from the information
center upon request when the vehicle approaches the blind area. The
acquired map information is stored in the memory and is read out
for use in navigation.
Inventors: |
HASHIMOTO, TAKAHIRO;
(SUSONO-SHI, JP) |
Correspondence
Address: |
FINNEGAN HENDERSON FARABOW
GARRETT & DUNNER
1300 I STREET NW
WASHINGTON
DC
20005
|
Family ID: |
18110900 |
Appl. No.: |
09/195917 |
Filed: |
November 19, 1998 |
Current U.S.
Class: |
701/409 ;
340/988; 342/357.34 |
Current CPC
Class: |
G08G 1/0969 20130101;
G01C 21/34 20130101 |
Class at
Publication: |
701/208 ;
701/213; 342/357.09; 340/988 |
International
Class: |
H04B 007/26 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 20, 1997 |
JP |
HEI 9-319498 |
Claims
What is claimed is:
1. An information acquisition system for acquiring map information
from an external source outside a vehicle, comprising: (a) storage
means for storing specifying data of a blind area in which the map
information is not acquirable; and (b) control means for acquiring,
based on said specifying data, the map information of said blind
area when the vehicle approaches said blind area.
2. An information acquisition system according to claim 1, further
comprising means for detecting a current position of the vehicle,
wherein said control means acquires the map information within a
predetermined range from said current position detected by said
detecting means.
3. An information acquisition system according to claim 2, wherein
said predetermined range is composed of a plurality of distance
steps for each of which said control means acquires a different
level of map information.
4. An information acquisition system according to claim 2, wherein
said predetermined range is composed of a plurality of distance
steps for each of which said control means acquires a different
level of map information to store the acquired map information in
said storage means commensurate with an unused capacity of said
storage means.
5. An information acquisition system according to claim 4, wherein
said control means deletes the map information of said blind area
after the vehicle has passed through said blind area.
6. An information acquisition system according to claim 1, further
comprising means for detecting a current position of the vehicle,
and means for searching an optimum route from the current position
of the vehicle to a destination, wherein if said blind area exists
on said optimum route, said control means acquires the map
information of said blind area.
7. An information acquisition system according to claim 6, wherein
if there exist in said optimum route a plurality of blind areas in
which the map information is not acquirable, said control means
acquires the map information of different levels each corresponding
to a distance between a respective one of said blind areas and the
current position of the vehicle.
8. An information acquisition system according to claim 6, wherein
if there exist in said optimum route a plurality of blind areas in
which the map information is not acquirable, said control means
acquires different levels of the map information, one for each of
said blind areas, to store the acquired map information in said
storage means commensurate with an unused capacity of said storage
means.
9. An information acquisition system according to claim 8, wherein
after the vehicle has passed through each of said blind areas, said
control means deletes the map information of each of said blind
areas.
10. An information acquisition system for acquiring map information
from an external information center outside a vehicle, comprising:
(a) a memory for storing specifying data of a blind area in which
the map information is not acquirable; (b) a processor for
acquiring, based on said specifying data, the map information of
said blind area when the vehicle approaches said blind area; and
(c) a communication device for requesting, based on a signal from
said processor, the external information center for the map
information and for receiving the map information transmitted from
the information center.
11. An information acquisition system according to claim 10,
wherein said memory has a first area for storing said specifying
data, a second area for storing data of a
map-information-acquirable area in which the map information is
acquirable from the external information center, and a third area
for storing the acquired map information.
12. An information acquisition system according to claim 10,
further comprising a detector for detecting a current position of
the vehicle, wherein said processor acquires the map information of
different levels commensurate with a distance from the current
position of the vehicle to said blind area.
13. An information acquisition system according to claim 12,
wherein if said blind area exists on an optimum route from the
current position of the vehicle to a destination, said processor
acquires the map information of different levels commensurate with
the distance from the current position of the vehicle to said blind
area.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention:
[0002] The present invention relates to an information acquisition
system, and more particularly to an information acquisition system
for acquiring necessary map data from an external information
center outside a vehicle.
[0003] 2. Description of the Related Art:
[0004] A technique for acquiring map data, which is to be used in
navigation of a vehicle, from an external information center is
currently known.
[0005] This prior art is exemplified by Japanese Patent Laid-Open
Publication No. Hei. 7-262493, which discloses a system for
distributing, through communication media between a vehicle and an
external information center, map information commensurate with the
degree of detail needed in smooth running of the vehicle. Namely,
the user requests distribution of detailed map information from the
information center as required, or the system automatically
requests detailed map information from the information center when
the vehicle comes leaves the area of the present detailed map
information. Thus the system receives the new map information newly
distributed from the information center.
[0006] However, if the vehicle runs into a blind area in which
detailed map information is not acquirable via any communication
media, then the vehicle cannot keep running smoothly without
consulting with the detailed map of the blind area.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide an
information acquisition system for acquiring map information of a
blind area, where the map information is not acquirable from an
external information center, without fail, even when the vehicle
runs in the blind area, thus enabling the vehicle to keep running
smoothly.
[0008] According to a first aspect of the invention, the above
object is accomplished by an information acquisition system for
acquiring map information from an external source outside a
vehicle, comprising: storage means for storing specifying data of a
blind area in which the map information is not acquirable; and
control means for acquiring, based on the specifying data, the map
information of the blind area when the vehicle approaches the blind
area. The map information includes, in addition to the map data,
data concerning various kinds of facilities (e.g. gas stations and
restaurants). The blind area is an area within which the vehicle
cannot receive the map information from the information center even
if it requests the information center to supply such information.
Before entering the blind area, the vehicle can acquire the map
information of the blind area to keep running smoothly even in the
blind area.
[0009] Preferably, the control means acquires the map information
within a predetermined range from the current position of the
vehicle. This predetermined range is preferably composed of a
plurality of distance steps for each of which the control means
acquires a different level of the map information. After the
vehicle has passed the blind area, the map information of the blind
area is no longer necessary, so it is preferable to delete the map
information of the blind area.
[0010] According to a second aspect of the invention, the above
object is accomplished by an information acquisition system for
acquiring map information from an external information center
outside a vehicle, comprising: a memory for storing specifying data
of a blind area in which the map information is not acquirable; a
processor for acquiring, based on the specifying data, the map
information of the blind area when the vehicle approaches the blind
area; and a communication device for requesting, based on a signal
from the processor, the external information center for the map
information and for receiving the map information transmitted from
the information center.
[0011] Preferably, the memory has a first area for storing the
specifying data, a second area for storing data of a
map-information-acquirable area in which the map information is
acquirable from the external information center, and a third area
for storing the acquired map information. The processor acquires
the map information of different levels commensurate with a
distance from the current position of the vehicle to the blind
area. If a blind area exists in a guide route from the current
position of the vehicle to a destination, the processor acquires
the map information of different levels commensurate with the
distance from the current position of the vehicle to the blind
area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a block diagram showing an information acquisition
system according to a first embodiment of the present
invention;
[0013] FIG. 2 is a diagram showing the structure of a data memory
of the system of the first embodiment;
[0014] FIG. 3 is a flowchart showing a first example of sequential
steps of operation of the system of the first embodiment;
[0015] FIG. 4 is a diagram to be used in showing the first
example;
[0016] FIG. 5 is a flowchart showing a second example of sequential
steps of operation of the system of the first embodiment;
[0017] FIG. 6 is a diagram to be used in showing the second
example;
[0018] FIG. 7 is a flowchart showing sequential steps of operation
of an information acquisition system according to a second
embodiment of the invention;
[0019] FIG. 8 is a diagram showing a first example of the
sequential steps of operation of the system of the second
embodiment; and
[0020] FIG. 9 is a diagram showing a second example of the
sequential steps of operation of the system of the second
embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Principles of the present invention are particularly useful
when applied to an information acquisition system for a vehicle,
preferred embodiments of which will now be described in detail with
reference to the accompanying drawings.
[0022] First Embodiment
[0023] FIG. 1 is a block diagram showing an information acquisition
system according to a first embodiment of the present invention.
The information acquisition system comprises a global positioning
system (GPS) 10, a sensor 12, a communication device 14, a control
unit 16, and a data memory 18, and an output device 20.
[0024] GPS 10 detects the position of a vehicle based on the
reception of position signals from an array of orbiting satellites,
and the output of the GPS 10 is supplied to the control unit
10.
[0025] The sensor 12 is a speed and/or direction sensor, or a fuel
sensor, which supplies detection signals to the control unit 16.
The detected direction and speed data, along with GPS signals, are
used in detecting the position of the vehicle. Namely, the position
of the vehicle is detected with high precision based on the
position data obtained from the GPS signals and the position
obtained from the detected direction and speed data.
[0026] The communication device 14 is a light or
electromagnetic-wave communication device or a mobile telephone for
requesting map information necessary for the vehicle from an
external information center 1, receiving the map information
transmitted from the information center 1 and supplying the
received map information to the control unit 16.
[0027] The control unit 16 is a micro computer for determining a
timing at which to request necessary map information from the
information center 1 via the communication device 14, inputting the
map information supplied from the communication device 14 and
storing the input map information in the data memory 18. The
control unit 16 executes a known navigational and surveying
function using the map data stored in the data memory 18 and
outputs on the output device 20 by displaying the map data read
from the data memory 18 and the detected position of the vehicle in
superimposition, or by surveying a guide route to a destination
inputted via an operation panel 22 and displaying the surveyed
guide route on the map data in superimposition.
[0028] The data memory 18 stores the map data obtained by the
control unit 16, has specifying data of a blind area, in which map
information is not acquirable from the information center 1,
already stored, and supplies this specifying data to the control
unit 16. The specifying data is to be used, along with the detected
position of the vehicle, in determination of the timing to request
the information center 1 for map information, and will be described
below more in detail. The data memory 18 is a reloadable storage
medium such as a magnetic disc, a semiconductor memory or an
optical disc.
[0029] FIG. 2 schematically shows a structure of the data memory
18. The data memory 18 has an acquirable data area 18a, a
non-acquirable data area 18b, and a specifying data area 18c.
[0030] In the acquirable data area 18a, map information, such as
map data and facility data, of a map-information-acquirable area or
region is to be stored as acquired from the information center 1 at
every request.
[0031] In the non-acquirable data area 18b, map data of a
map-information-non-acquirable or blind region or area where
electric waves from the information center 1 cannot reach the
vehicle is to be stored as acquired from the information center 1
at request before the vehicle enters the blind area. The empty
capacity of the non-acquirable data area 18b serves as a factor
determining which quantity of map information is previously
acquirable.
[0032] In the specifying data area 18c, specifying data specifying
the blind area is to be previously stored. The specifying data is
exemplified by center-position data and radius data as defined in
terms of the range of latitude and longitude. The control unit 16
reads the specifying data from the specifying data area 18c for use
in determining the timing at which the map information of the blind
area is to be requested to the information center 1.
[0033] The operation of the control unit 16 will now be
described.
[0034] FIG. 3 is a flowchart showing sequential steps to be
executed by the control unit 16. Firstly, the control unit 16
confirms whether or not a blind area, in which map information such
as map data and facility data cannot be acquired in real time,
exists within a constant distance from a current position C of the
vehicle (S101). This step is accomplished by comparing the detected
current position C of the vehicle with a predetermined distance
(e.g. 100 km) and the specifying data stored in data memory 18. The
predetermined distance may be set as either a single distance step
or a plurality of distance steps.
[0035] If the predetermined distance is set as a plurality of
distance steps, the control unit 16 defines the predetermined
distance as Li (1.ltoreq.i.ltoreq.n, L1<L2<L2) and the blind
area corresponding to Li as Ni. The control unit 16 then
initializes a variable .alpha. to 1 (S102) and increments the
variable .alpha. 1 by 1 to obtain information of successive blind
areas N.alpha. in order (S103, S104, S105).
[0036] FIG. 4 schematically shows the manner in which the map
information is acquired in step S103. In FIG. 4, it is assumed that
a map-information-acquirable area 100, in which map information can
be acquired in real time with respect to the current position C of
the vehicle, exists, and a blind area 102, in which the map
information cannot be acquired with real time with respect to the
current position C of the vehicle, also exists. Generally, when the
vehicle is located at the current position C, a request is
transmitted to the information center 1 to acquire the map
information (i.e. map data and facility data) of a region 104
indicated by a dash-and-dot line. If the blind area 102 exists
within a predetermined distance (a region 106 covering, for
example, 100 km from the current position C of the vehicle), the
map information of the blind area 102 would be not acquirable in
real time after it has entered the blind area 102. Consequently,
when the vehicle approaches the blind area 102, namely, when the
current position C of the vehicle is located within the
map-information-acquirable area 100, a request is transmitted to
the information center 1 to previously acquire the map information
of a partial blind area 108 (i.e. N.alpha.) located within the
region 106 from the predetermined distance with respect to the
current position C of the vehicle. Even when it has entered the
blind area 108, the vehicle can keep running smoothly by using the
information stored in the data memory 18.
[0037] If the predetermined distance is set as a plurality of
distance steps, it is also desirable to acquire the map information
of different levels one for every step of a predetermined distance
instead of acquiring the same level of information for every
N.alpha..
[0038] FIG. 5 is a flowchart showing sequential steps in which map
information of different levels is acquired one for each step of a
predetermined distance. Firstly, discrimination is made as to
whether or not .alpha. is 1 (S201), and if .alpha. is 1, namely,
with respect to the blind area nearest to the current position C of
the vehicle, detailed map information including small streets is
acquired (S202). If .alpha. is 2 or more, map information of only
main roads is acquired as the blind area is relatively far from the
current position C of the vehicle (S203).
[0039] FIG. 6 schematically show the manner in which the map
information is acquired in steps S202, S203. Two predetermined
distance steps are set from the current position C of the vehicle
in such a manner that the first step corresponds to a first region
106 (e.g. 100 km away from the vehicle) and the second step
corresponds to a second region 107 (e.g. 200 km away from the
vehicle). With respect to a blind area 108 (i.e. N1) located within
the first step, a request is transmitted to the information center
to acquire detailed map information including small streets. With
respect to a blind area 110 (i.e. N2) located within the second
step, a request is transmitted to the information center to acquire
map information of only main roads. The acquired information is
then stored in the map-information-non-acquirable data area 18b of
the data memory 18.
[0040] Thus since different levels of the map information vary
stepwise according to the predetermined distance steps (according
to the distance from the current position C of the vehicle) in such
a manner that the farther the distance from the vehicle, the
simpler the map information level, it is possible to use the
map-information-non-acquirable data area 18b of the data memory 18
efficiently.
[0041] Thus, since different levels of the map information vary
stepwise according to the predetermined distance steps (according
to the distance from the current position C of the vehicle) in such
a manner that the farther the distance from the vehicle, the
simpler the map information level, it is possible to use the
map-information-non-acquirable data area 18b of the data memory 18
efficiently.
[0042] If the predetermined distance of the blind area is set to
two or more distance steps N.alpha. and if there is sufficient
capacity of the map-information-non-acquirable data area 18b of the
data memory 18, detailed map information including small streets is
acquired for every N.alpha.. Only if there is no room in the
map-information-non-acquirable data area 18b, it is also desirable
to acquire different levels of map information for each step of the
predetermined distance.
[0043] In this embodiment, the distance from the current position
of the vehicle may be varied commensurate with the vehicle speed
detected by the sensor 12, instead of being fixed. Specifically,
the higher the speed of the vehicle, the larger the predetermined
distance may be increased. Of course, the unused capacity of the
map-information-non-acquirable data area 18b of the data memory 1
may be checked, and the predetermined distance may be set according
to the unused capacity.
[0044] Also in this embodiment, facility data may be acquired as
map information. Specifically, when a blind area exists in a guide
route and when the remaining amount of fuel as calculated by the
sensor 12 is expected near this blind area, the information of gas
stations existing in the blind area is previously requested and
acquired from the information center.
[0045] Further in this embodiment, when the vehicle has passed
through the blind area whose map information was previously
acquired from the information center, it is desirable to delete the
map information stored in the map-information-non-acquirable data
area 18b of the data memory 18, securing adequate memory
capacity.
[0046] Second Embodiment
[0047] FIG. 7 is a flowchart showing sequential steps of operation
of the control unit 16. In the first embodiment, a guide route (a
recommended route) is set. In the second embodiment, however, a
guide route to a destination is set, namely, an area for the
vehicle to run is limited.
[0048] The control unit 16 calculates a guide route R from a
starting point O to a destination D using the map data stored in
the data memory 18 (S301). The control unit 16 then confirms
whether or not a blind area, in which map information is not
acquirable from the information center with real time, exists in
the guide route R (S302), comparing the guide route R with
specifying data previously stored in the data memory 18. If a
plurality of blind areas exist in the guide route R, the control
unit 16 sets these blind areas as Ri (1.ltoreq.i.ltoreq.n) in the
order of increasing distance from the starting point 0.
[0049] The control unit 16 then initializes each of variables
.alpha. and .beta. to 1 (S303) and confirms whether or not unused
capacity sufficient to store the information remains in the
map-information-non-acquirable data area 18b of the data memory 18
(s304). If sufficient unused capacity remains, the control unit 16
requests and acquires from the information center map information
of a surrounding section N.alpha. (e.g. an area covering a width of
10 km from the guide route) within a predetermined range of
R.alpha. (S305). After having acquired the information concerning
R.alpha., the control unit 16 increments the variable .alpha. 1 by
1 (S306) and guides the vehicle using the acquired map data
(S307).
[0050] With continued running of the vehicle, the control unit 16
discriminates whether or not the running vehicle has passed through
R.beta. (i.e. the blind area whose information was acquired in step
S305) (S308). While the vehicle is still running in R.beta., the
control unit 16 repeats the steps S303 to S307 to acquire the map
information of the successive surrounding sections R.alpha. one
after another.
[0051] On the contrary, if the vehicle has passed through R.beta.,
then the map information of N.alpha. is no longer necessary;
consequently the control unit 16 deletes the map information of
N.alpha. from the map-information-non-acquirable data area 18b of
the data memory 18 to increase the unused capacity of the
map-information-non-acquirable data area 18b (S309). The control
unit 16 then increments .beta. by only 1 (S310) and repeats the
steps S304 to S310 until the vehicle reaches the destination D to
terminate the navigation (S311).
[0052] The foregoing procedure is schematically shown by FIGS. 8
and 9. FIG. 8 illustrates one case in which only a single blind
area exists, and FIG. 9 illustrates another case in which a
plurality of (two) blind areas exist. In FIG. 8, if a blind area
102 in which map information cannot be acquired from the
information center in real time exists on a guide route 101 from
the starting point O to the destination D, the control unit 16
transmits a request to the information center to previously acquire
the information of a peripheral section 112 of the guide route 101
within the blind area 102. The control unit 16 then stores the
acquired information in the map-information-non-acquirable data
area 18b of the data memory 18. Therefore, even when the vehicle is
running in the blind area 102, the vehicle can be navigated using
the previously acquired map information.
[0053] In FIG. 9, if first and second blind areas 102a, 102b, in
which map information cannot be acquired from the information
center in real time, exist in a guide route 101 from the starting
point O to the destination D, the control unit 16 first confirms
that the unused capacity of the map-information-non-acquirable data
area 18b of the data memory 18 is sufficient to store map
information concerning the first blind area 102a, then acquires and
stores the information in the map-information-non-acqui- rable data
area 18b. The control unit 16 then reconfirms whether or not the
unused capacity of the map-information-non-acquirable data area 18b
is still sufficient, and acquires the map information concerning
the second blind area 102b if the remaining unused capacity is
sufficient. If the remaining unused capacity is not sufficient, the
control unit 16 waits until after the vehicle has passed through
the first blind area 102a, then deletes the map information of the
first blind area 102a from the map-information-non-acquirable data
area 18b after the vehicle has passed through the first blind area
102a, whereupon the control unit 16 acquires the information
concerning the second blind area 102b.
[0054] Therefore, even when a blind area, in which map information
such as map data and facility data cannot be acquired from the
information center, exists in the guide route, the vehicle can keep
running smoothly using the previously acquired map information of
the blind area.
[0055] In this embodiment, like the first embodiment, the
predetermined distance may be set as a plurality of distance steps
so that the farther the distance from the guide route, the simpler
the level of map information that may be acquired.
[0056] Further, in FIG. 9, if the capacity of the data memory is
not sufficient in the presence of the blind areas 102a, 102b in the
guide route, the control unit 16 can acquire the map information
including small streets with respect to the first blind area 102a
and the map information of simple level concerning only main
roads.
[0057] In the foregoing embodiments, the system acquires every map
data from the information center. The present invention may be
applied to a system in which wide-area map data are previously
stored in the data memory 18 and only detailed map data are
acquired from the information center as required.
[0058] According to the information acquisition system of the
present invention, since the system previously acquires the map
information concerning a blind area from the information center
when the vehicle approaches the blind area, the vehicle can keep
running smoothly in the blind area.
* * * * *